diff --git a/lib/Slic3r/GUI/Plater.pm b/lib/Slic3r/GUI/Plater.pm
index e15b8c34c..e6b2fca79 100644
--- a/lib/Slic3r/GUI/Plater.pm
+++ b/lib/Slic3r/GUI/Plater.pm
@@ -53,7 +53,7 @@ sub new {
         bed_shape complete_objects extruder_clearance_radius skirts skirt_distance brim_width variable_layer_height
         serial_port serial_speed octoprint_host octoprint_apikey octoprint_cafile
         nozzle_diameter single_extruder_multi_material wipe_tower wipe_tower_x wipe_tower_y wipe_tower_width
-	wipe_tower_rotation_angle extruder_colour filament_colour max_print_height
+	wipe_tower_rotation_angle extruder_colour filament_colour max_print_height printer_model
     )]);
     # C++ Slic3r::Model with Perl extensions in Slic3r/Model.pm
     $self->{model} = Slic3r::Model->new;
@@ -187,6 +187,7 @@ sub new {
     if ($Slic3r::GUI::have_OpenGL) {
         $self->{preview3D} = Slic3r::GUI::Plater::3DPreview->new($self->{preview_notebook}, $self->{print}, $self->{gcode_preview_data}, $self->{config});
         Slic3r::GUI::_3DScene::set_active($self->{preview3D}->canvas, 0);
+        Slic3r::GUI::_3DScene::enable_legend_texture($self->{preview3D}->canvas, 1);
         Slic3r::GUI::_3DScene::register_on_viewport_changed_callback($self->{preview3D}->canvas, sub { Slic3r::GUI::_3DScene::set_viewport_from_scene($self->{canvas3D}, $self->{preview3D}->canvas); });
         $self->{preview_notebook}->AddPage($self->{preview3D}, L('Preview'));
         $self->{preview3D_page_idx} = $self->{preview_notebook}->GetPageCount-1;
@@ -200,17 +201,18 @@ sub new {
     
     EVT_NOTEBOOK_PAGE_CHANGED($self, $self->{preview_notebook}, sub {
         my $preview = $self->{preview_notebook}->GetCurrentPage;
-        if ($preview == $self->{preview3D})
-        {
+        if (($preview != $self->{preview3D}) && ($preview != $self->{canvas3D})) {
+            Slic3r::GUI::_3DScene::set_active($self->{preview3D}->canvas, 0);
+            Slic3r::GUI::_3DScene::set_active($self->{canvas3D}, 0);
+            Slic3r::GUI::_3DScene::reset_current_canvas();
+            $preview->OnActivate if $preview->can('OnActivate');        
+        } elsif ($preview == $self->{preview3D}) {
             Slic3r::GUI::_3DScene::set_active($self->{preview3D}->canvas, 1);
             Slic3r::GUI::_3DScene::set_active($self->{canvas3D}, 0);
-            Slic3r::GUI::_3DScene::enable_legend_texture($self->{preview3D}->canvas, 1);
-            $self->{preview3D}->load_print(1);
-        } else {
-            Slic3r::GUI::_3DScene::enable_legend_texture($self->{preview3D}->canvas, 0);
-        }
-
-        if ($preview == $self->{canvas3D}) {
+            $self->{preview3D}->load_print;
+            # sets the canvas as dirty to force a render at the 1st idle event (wxWidgets IsShownOnScreen() is buggy and cannot be used reliably)
+            Slic3r::GUI::_3DScene::set_as_dirty($self->{preview3D}->canvas);
+        } elsif ($preview == $self->{canvas3D}) {
             Slic3r::GUI::_3DScene::set_active($self->{canvas3D}, 1);
             Slic3r::GUI::_3DScene::set_active($self->{preview3D}->canvas, 0);
             if (Slic3r::GUI::_3DScene::is_reload_delayed($self->{canvas3D})) {
@@ -218,8 +220,8 @@ sub new {
                 Slic3r::GUI::_3DScene::set_objects_selections($self->{canvas3D}, \@$selections);
                 Slic3r::GUI::_3DScene::reload_scene($self->{canvas3D}, 1);
             }            
-        } else {
-            $preview->OnActivate if $preview->can('OnActivate');        
+            # sets the canvas as dirty to force a render at the 1st idle event (wxWidgets IsShownOnScreen() is buggy and cannot be used reliably)
+            Slic3r::GUI::_3DScene::set_as_dirty($self->{canvas3D});
         }
     });
     
@@ -1886,6 +1888,9 @@ sub on_config_change {
             $self->{preview3D}->set_number_extruders(scalar(@{$extruder_colors}));
         } elsif ($opt_key eq 'max_print_height') {
             $update_scheduled = 1;
+        } elsif ($opt_key eq 'printer_model') {
+            # update to force bed selection (for texturing)
+            $update_scheduled = 1;
         }
     }
 
diff --git a/lib/Slic3r/GUI/Plater/2D.pm b/lib/Slic3r/GUI/Plater/2D.pm
index ad8f54ddb..83c2a5021 100644
--- a/lib/Slic3r/GUI/Plater/2D.pm
+++ b/lib/Slic3r/GUI/Plater/2D.pm
@@ -231,8 +231,10 @@ sub mouse_event {
         }
         $self->Refresh;
     } elsif ($event->LeftUp) {
-        $self->{on_instances_moved}->()
-            if $self->{drag_object};
+        if ($self->{drag_object}) {
+            $self->{on_instances_moved}->();
+            Slic3r::GUI::_3DScene::reset_current_canvas();            
+        }
         $self->{drag_start_pos} = undef;
         $self->{drag_object} = undef;
         $self->SetCursor(wxSTANDARD_CURSOR);
diff --git a/xs/src/avrdude/arduino.c b/xs/src/avrdude/arduino.c
index fc9f4571f..5a9cb465e 100644
--- a/xs/src/avrdude/arduino.c
+++ b/xs/src/avrdude/arduino.c
@@ -99,7 +99,7 @@ static int prusa_init_external_flash(PROGRAMMER * pgm)
     avrdude_message(MSG_INFO, "%s: prusa_init_external_flash(): MK3 printer did not boot up on time or serial communication failed\n", progname);
     return -1;
   } else if (strncmp(buffer, entry_magic_send, recv_size) != 0) {
-    avrdude_message(MSG_INFO, "%s: prusa_init_external_flash(): MK3 printer emitted incorrect start code\n", progname);
+    avrdude_message(MSG_INFO, "%s: prusa_init_external_flash(): MK3 printer emitted incorrect start code: `%*s`\n", progname, recv_size, buffer);
     return -1;
   }
 
@@ -116,7 +116,7 @@ static int prusa_init_external_flash(PROGRAMMER * pgm)
     avrdude_message(MSG_INFO, "%s: prusa_init_external_flash(): MK3 printer did not boot up on time or serial communication failed\n", progname);
     return -1;
   } else if (strncmp(buffer, entry_magic_cfm, recv_size) != 0) {
-    avrdude_message(MSG_INFO, "%s: prusa_init_external_flash(): MK3 printer emitted incorrect start code\n", progname);
+    avrdude_message(MSG_INFO, "%s: prusa_init_external_flash(): MK3 printer emitted incorrect cfm code: `%*s`\n", progname, recv_size, buffer);
     return -1;
   }
 
@@ -140,6 +140,13 @@ static int arduino_open(PROGRAMMER * pgm, char * port)
   serial_set_dtr_rts(&pgm->fd, 1);
   usleep(50*1000);
 
+  // Sometimes there may be line noise generating input on the printer's USB-to-serial IC
+  // Here we try to clean its input buffer with a sequence of newlines (a minimum of 9 is needed):
+  const char cleanup_newlines[] = "\n\n\n\n\n\n\n\n\n\n";
+  if (serial_send(&pgm->fd, cleanup_newlines, sizeof(cleanup_newlines) - 1) < 0) {
+    return -1;
+  }
+
   /*
    * drain any extraneous input
    */
diff --git a/xs/src/libslic3r/GCode/WipeTowerPrusaMM.cpp b/xs/src/libslic3r/GCode/WipeTowerPrusaMM.cpp
index 6486f2917..fbde83754 100644
--- a/xs/src/libslic3r/GCode/WipeTowerPrusaMM.cpp
+++ b/xs/src/libslic3r/GCode/WipeTowerPrusaMM.cpp
@@ -142,24 +142,21 @@ public:
 		}
 
 		m_gcode += "G1";
-		if (rot.x != rotated_current_pos.x) {
-			m_gcode += set_format_X(rot.x);     // Transform current position back to wipe tower coordinates (was updated by set_format_X)
-            m_current_pos.x = x;
-        }
-		if (rot.y != rotated_current_pos.y) {
+		if (std::abs(dx) > EPSILON)
+			m_gcode += set_format_X(rot.x);
+
+		if (std::abs(dy) > EPSILON)
 			m_gcode += set_format_Y(rot.y);
-            m_current_pos.y = y;
-        }
 
 		if (e != 0.f)
 			m_gcode += set_format_E(e);
 
 		if (f != 0.f && f != m_current_feedrate)
 			m_gcode += set_format_F(f);
-		
-		
-		
-		
+
+        m_current_pos.x = x;
+        m_current_pos.y = y;
+
 		// Update the elapsed time with a rough estimate.
 		m_elapsed_time += ((len == 0) ? std::abs(e) : len) / m_current_feedrate * 60.f;
 		m_gcode += "\n";
diff --git a/xs/src/slic3r/GUI/3DScene.cpp b/xs/src/slic3r/GUI/3DScene.cpp
index 1879b3082..a499825a4 100644
--- a/xs/src/slic3r/GUI/3DScene.cpp
+++ b/xs/src/slic3r/GUI/3DScene.cpp
@@ -433,6 +433,7 @@ std::vector<int> GLVolumeCollection::load_object(
                     v.extruder_id = extruder_id;
             }
             v.is_modifier = model_volume->modifier;
+            v.outside_printer_detection_enabled = !model_volume->modifier;
         }
     }
     
@@ -663,7 +664,7 @@ bool GLVolumeCollection::check_outside_state(const DynamicPrintConfig* config)
     bool contained = true;
     for (GLVolume* volume : this->volumes)
     {
-        if (volume != nullptr)
+        if ((volume != nullptr) && !volume->is_modifier)
         {
             bool state = print_volume.contains(volume->transformed_bounding_box());
             contained &= state;
@@ -1753,11 +1754,26 @@ bool _3DScene::init(wxGLCanvas* canvas)
     return s_canvas_mgr.init(canvas);
 }
 
+bool _3DScene::set_current(wxGLCanvas* canvas, bool force)
+{
+    return s_canvas_mgr.set_current(canvas, force);
+}
+
+void _3DScene::reset_current_canvas()
+{
+    s_canvas_mgr.set_current(nullptr, false);
+}
+
 void _3DScene::set_active(wxGLCanvas* canvas, bool active)
 {
     s_canvas_mgr.set_active(canvas, active);
 }
 
+void _3DScene::set_as_dirty(wxGLCanvas* canvas)
+{
+    s_canvas_mgr.set_as_dirty(canvas);
+}
+
 unsigned int _3DScene::get_volumes_count(wxGLCanvas* canvas)
 {
     return s_canvas_mgr.get_volumes_count(canvas);
diff --git a/xs/src/slic3r/GUI/3DScene.hpp b/xs/src/slic3r/GUI/3DScene.hpp
index c6a166397..f45bab276 100644
--- a/xs/src/slic3r/GUI/3DScene.hpp
+++ b/xs/src/slic3r/GUI/3DScene.hpp
@@ -516,7 +516,11 @@ public:
 
     static bool init(wxGLCanvas* canvas);
 
+    static bool set_current(wxGLCanvas* canvas, bool force);
+    static void reset_current_canvas();
+
     static void set_active(wxGLCanvas* canvas, bool active);
+    static void set_as_dirty(wxGLCanvas* canvas);
 
     static unsigned int get_volumes_count(wxGLCanvas* canvas);
     static void reset_volumes(wxGLCanvas* canvas);
diff --git a/xs/src/slic3r/GUI/Field.cpp b/xs/src/slic3r/GUI/Field.cpp
index 43c9e7db9..85247b41b 100644
--- a/xs/src/slic3r/GUI/Field.cpp
+++ b/xs/src/slic3r/GUI/Field.cpp
@@ -12,10 +12,20 @@ namespace Slic3r { namespace GUI {
 
 	wxString double_to_string(double const value)
 	{
-		int precision = 10 * value - int(10 * value) == 0 ? 1 : 2;
-		return value - int(value) == 0 ?
-			wxString::Format(_T("%i"), int(value)) :
-			wxNumberFormatter::ToString(value, precision, wxNumberFormatter::Style_None);
+		if (value - int(value) == 0)
+			return wxString::Format(_T("%i"), int(value));
+		else {
+			int precision = 4;
+			for (size_t p = 1; p < 4; p++)
+			{
+				double cur_val = pow(10, p)*value;
+				if (cur_val - int(cur_val) == 0) {
+					precision = p;
+					break;
+				}
+			}
+			return wxNumberFormatter::ToString(value, precision, wxNumberFormatter::Style_None);
+		}
 	}
 
 	void Field::PostInitialize(){
diff --git a/xs/src/slic3r/GUI/GLCanvas3D.cpp b/xs/src/slic3r/GUI/GLCanvas3D.cpp
index f9c10017e..f5db97731 100644
--- a/xs/src/slic3r/GUI/GLCanvas3D.cpp
+++ b/xs/src/slic3r/GUI/GLCanvas3D.cpp
@@ -405,16 +405,27 @@ GLCanvas3D::Bed::EType GLCanvas3D::Bed::_detect_type() const
     const PresetBundle* bundle = get_preset_bundle();
     if (bundle != nullptr)
     {
-        const Preset& curr = bundle->printers.get_selected_preset();
-        if (curr.config.has("bed_shape") && _are_equal(m_shape, dynamic_cast<const ConfigOptionPoints*>(curr.config.option("bed_shape"))->values))
+        const Preset* curr = &bundle->printers.get_selected_preset();
+        while (curr != nullptr)
         {
-            if ((curr.vendor != nullptr) && (curr.vendor->name == "Prusa Research"))
+            if (curr->config.has("bed_shape") && _are_equal(m_shape, dynamic_cast<const ConfigOptionPoints*>(curr->config.option("bed_shape"))->values))
             {
-                if (boost::contains(curr.name, "MK2"))
-                    type = MK2;
-                else if (boost::contains(curr.name, "MK3"))
-                    type = MK3;
+                if ((curr->vendor != nullptr) && (curr->vendor->name == "Prusa Research"))
+                {
+                    if (boost::contains(curr->name, "MK2"))
+                    {
+                        type = MK2;
+                        break;
+                    }
+                    else if (boost::contains(curr->name, "MK3"))
+                    {
+                        type = MK3;
+                        break;
+                    }
+                }
             }
+
+            curr = bundle->printers.get_preset_parent(*curr);
         }
     }
 
@@ -1509,13 +1520,10 @@ bool GLCanvas3D::init(bool useVBOs, bool use_legacy_opengl)
     return true;
 }
 
-bool GLCanvas3D::set_current()
+bool GLCanvas3D::set_current(bool force)
 {
-    if ((m_canvas != nullptr) && (m_context != nullptr))
-    {
-        m_canvas->SetCurrent(*m_context);
-        return true;
-    }
+    if ((force || m_active) && (m_canvas != nullptr) && (m_context != nullptr))
+        return m_canvas->SetCurrent(*m_context);
 
     return false;
 }
@@ -1525,6 +1533,11 @@ void GLCanvas3D::set_active(bool active)
     m_active = active;
 }
 
+void GLCanvas3D::set_as_dirty()
+{
+    m_dirty = true;
+}
+
 unsigned int GLCanvas3D::get_volumes_count() const
 {
     return (unsigned int)m_volumes.volumes.size();
@@ -1532,8 +1545,13 @@ unsigned int GLCanvas3D::get_volumes_count() const
 
 void GLCanvas3D::reset_volumes()
 {
-    if (set_current())
+
+    if (!m_volumes.empty())
     {
+        // ensures this canvas is current
+        if ((m_canvas == nullptr) || !_3DScene::set_current(m_canvas, true))
+            return;
+
         m_volumes.release_geometry();
         m_volumes.clear();
         m_dirty = true;
@@ -1831,8 +1849,8 @@ void GLCanvas3D::render()
     if (!_is_shown_on_screen())
         return;
 
-    // ensures that the proper context is selected and that this canvas is initialized
-    if (!set_current() || !_3DScene::init(m_canvas))
+    // ensures this canvas is current and initialized
+    if (!_3DScene::set_current(m_canvas, false) || !_3DScene::init(m_canvas))
         return;
 
     if (m_force_zoom_to_bed_enabled)
@@ -1913,6 +1931,11 @@ void GLCanvas3D::reload_scene(bool force)
         return;
 
     reset_volumes();
+
+    // ensures this canvas is current
+    if (!_3DScene::set_current(m_canvas, true))
+        return;
+
     set_bed_shape(dynamic_cast<const ConfigOptionPoints*>(m_config->option("bed_shape"))->values);
 
     if (!m_canvas->IsShown() && !force)
@@ -1984,6 +2007,10 @@ void GLCanvas3D::reload_scene(bool force)
 
 void GLCanvas3D::load_print_toolpaths()
 {
+    // ensures this canvas is current
+    if (!_3DScene::set_current(m_canvas, true))
+        return;
+
     if (m_print == nullptr)
         return;
 
@@ -2348,8 +2375,8 @@ void GLCanvas3D::load_gcode_preview(const GCodePreviewData& preview_data, const
 {
     if ((m_canvas != nullptr) && (m_print != nullptr))
     {
-        // ensures that the proper context is selected
-        if (!set_current())
+        // ensures that this canvas is current
+        if (!_3DScene::set_current(m_canvas, false))
             return;
 
         if (m_volumes.empty())
@@ -2666,7 +2693,11 @@ void GLCanvas3D::on_mouse(wxMouseEvent& evt)
 #endif
     } 
     else if (evt.LeftDClick() && (m_hover_volume_id != -1))
+    {
+        m_active = false;
         m_on_double_click_callback.call();
+        m_active = true;
+    }
     else if (evt.LeftDown() || evt.RightDown())
     {
         // If user pressed left or right button we first check whether this happened
@@ -2762,7 +2793,11 @@ void GLCanvas3D::on_mouse(wxMouseEvent& evt)
                 {
                     // if right clicking on volume, propagate event through callback
                     if (m_volumes.volumes[volume_idx]->hover)
+                    {
+                        m_active = false;
                         m_on_right_click_callback.call(pos.x, pos.y);
+                        m_active = true;
+                    }
                 }
             }
         }
@@ -2980,10 +3015,11 @@ void GLCanvas3D::_force_zoom_to_bed()
 
 void GLCanvas3D::_resize(unsigned int w, unsigned int h)
 {
-    if (m_context == nullptr)
+    if ((m_canvas == nullptr) && (m_context == nullptr))
         return;
 
-    set_current();
+    // ensures that this canvas is current
+    _3DScene::set_current(m_canvas, false);
     ::glViewport(0, 0, w, h);
 
     ::glMatrixMode(GL_PROJECTION);
@@ -3569,9 +3605,11 @@ void GLCanvas3D::_perform_layer_editing_action(wxMouseEvent* evt)
 
 Pointf3 GLCanvas3D::_mouse_to_3d(const Point& mouse_pos, float* z)
 {
-    if (!set_current())
+    if (m_canvas == nullptr)
         return Pointf3(DBL_MAX, DBL_MAX, DBL_MAX);
 
+    _camera_tranform();
+
     GLint viewport[4];
     ::glGetIntegerv(GL_VIEWPORT, viewport);
     GLdouble modelview_matrix[16];
diff --git a/xs/src/slic3r/GUI/GLCanvas3D.hpp b/xs/src/slic3r/GUI/GLCanvas3D.hpp
index c503d1845..237044e83 100644
--- a/xs/src/slic3r/GUI/GLCanvas3D.hpp
+++ b/xs/src/slic3r/GUI/GLCanvas3D.hpp
@@ -449,9 +449,10 @@ public:
 
     bool init(bool useVBOs, bool use_legacy_opengl);
 
-    bool set_current();
+    bool set_current(bool force);
 
     void set_active(bool active);
+    void set_as_dirty();
 
     unsigned int get_volumes_count() const;
     void reset_volumes();
diff --git a/xs/src/slic3r/GUI/GLCanvas3DManager.cpp b/xs/src/slic3r/GUI/GLCanvas3DManager.cpp
index bdca73854..62d17827a 100644
--- a/xs/src/slic3r/GUI/GLCanvas3DManager.cpp
+++ b/xs/src/slic3r/GUI/GLCanvas3DManager.cpp
@@ -115,6 +115,7 @@ std::string GLCanvas3DManager::GLInfo::to_string(bool format_as_html, bool exten
 
 GLCanvas3DManager::GLCanvas3DManager()
     : m_context(nullptr)
+    , m_current(nullptr)
     , m_gl_initialized(false)
     , m_use_legacy_opengl(false)
     , m_use_VBOs(false)
@@ -212,6 +213,34 @@ bool GLCanvas3DManager::init(wxGLCanvas* canvas)
         return false;
 }
 
+bool GLCanvas3DManager::set_current(wxGLCanvas* canvas, bool force)
+{
+    // given canvas is already current, return
+    if (m_current == canvas)
+        return true;
+
+    if (canvas == nullptr)
+    {
+        m_current = nullptr;
+        return true;
+    }
+
+    // set given canvas as current
+    CanvasesMap::iterator it = _get_canvas(canvas);
+    if (it != m_canvases.end())
+    {
+        bool res = it->second->set_current(force);
+        if (res)
+        {
+            m_current = canvas;
+            return true;
+        }
+    }
+
+    m_current = nullptr;
+    return false;
+}
+
 void GLCanvas3DManager::set_active(wxGLCanvas* canvas, bool active)
 {
     CanvasesMap::iterator it = _get_canvas(canvas);
@@ -219,6 +248,13 @@ void GLCanvas3DManager::set_active(wxGLCanvas* canvas, bool active)
         it->second->set_active(active);
 }
 
+void GLCanvas3DManager::set_as_dirty(wxGLCanvas* canvas)
+{
+    CanvasesMap::iterator it = _get_canvas(canvas);
+    if (it != m_canvases.end())
+        it->second->set_as_dirty();
+}
+
 unsigned int GLCanvas3DManager::get_volumes_count(wxGLCanvas* canvas) const
 {
     CanvasesMap::const_iterator it = _get_canvas(canvas);
diff --git a/xs/src/slic3r/GUI/GLCanvas3DManager.hpp b/xs/src/slic3r/GUI/GLCanvas3DManager.hpp
index 3092925d3..35a1db206 100644
--- a/xs/src/slic3r/GUI/GLCanvas3DManager.hpp
+++ b/xs/src/slic3r/GUI/GLCanvas3DManager.hpp
@@ -45,6 +45,7 @@ class GLCanvas3DManager
 
     wxGLContext* m_context;
     CanvasesMap m_canvases;
+    wxGLCanvas* m_current;
     GLInfo m_gl_info;
     bool m_gl_initialized;
     bool m_use_legacy_opengl;
@@ -69,7 +70,9 @@ public:
 
     bool init(wxGLCanvas* canvas);
 
+    bool set_current(wxGLCanvas* canvas, bool force);
     void set_active(wxGLCanvas* canvas, bool active);
+    void set_as_dirty(wxGLCanvas* canvas);
 
     unsigned int get_volumes_count(wxGLCanvas* canvas) const;
     void reset_volumes(wxGLCanvas* canvas);
diff --git a/xs/src/slic3r/GUI/GLTexture.cpp b/xs/src/slic3r/GUI/GLTexture.cpp
index 593362e54..924920bd8 100644
--- a/xs/src/slic3r/GUI/GLTexture.cpp
+++ b/xs/src/slic3r/GUI/GLTexture.cpp
@@ -4,6 +4,8 @@
 
 #include <wx/image.h>
 
+#include <boost/filesystem.hpp>
+
 #include <vector>
 #include <algorithm>
 
@@ -27,6 +29,9 @@ bool GLTexture::load_from_file(const std::string& filename, bool generate_mipmap
 {
     reset();
 
+    if (!boost::filesystem::exists(filename))
+        return false;
+
     // Load a PNG with an alpha channel.
     wxImage image;
     if (!image.LoadFile(filename, wxBITMAP_TYPE_PNG))
diff --git a/xs/src/slic3r/GUI/GUI.cpp b/xs/src/slic3r/GUI/GUI.cpp
index e2f3925fc..c1f8adaf1 100644
--- a/xs/src/slic3r/GUI/GUI.cpp
+++ b/xs/src/slic3r/GUI/GUI.cpp
@@ -56,6 +56,7 @@
 
 #include "../Utils/PresetUpdater.hpp"
 #include "../Config/Snapshot.hpp"
+#include "3DScene.hpp"
 
 
 namespace Slic3r { namespace GUI {
@@ -378,6 +379,7 @@ void add_config_menu(wxMenuBar *menu, int event_preferences_changed, int event_l
 				save_language();
 				show_info(g_wxTabPanel, _(L("Application will be restarted")), _(L("Attention!")));
 				if (event_language_change > 0) {
+					_3DScene::remove_all_canvases();// remove all canvas before recreate GUI
 					wxCommandEvent event(event_language_change);
 					g_wxApp->ProcessEvent(event);
 				}
diff --git a/xs/src/slic3r/GUI/MsgDialog.hpp b/xs/src/slic3r/GUI/MsgDialog.hpp
index 2d570a0bf..ca349eb5c 100644
--- a/xs/src/slic3r/GUI/MsgDialog.hpp
+++ b/xs/src/slic3r/GUI/MsgDialog.hpp
@@ -28,6 +28,8 @@ struct MsgDialog : wxDialog
 	MsgDialog &operator=(const MsgDialog &) = delete;
 	virtual ~MsgDialog();
 
+	// TODO: refactor with CreateStdDialogButtonSizer usage
+
 protected:
 	enum {
 		CONTENT_WIDTH = 500,
diff --git a/xs/src/slic3r/GUI/Tab.cpp b/xs/src/slic3r/GUI/Tab.cpp
index 6eabc2f47..94f8cc3ea 100644
--- a/xs/src/slic3r/GUI/Tab.cpp
+++ b/xs/src/slic3r/GUI/Tab.cpp
@@ -2619,14 +2619,24 @@ void SavePresetWindow::accept()
 	if (!m_chosen_name.empty()) {
 		const char* unusable_symbols = "<>:/\\|?*\"";
 		bool is_unusable_symbol = false;
+		bool is_unusable_postfix = false;
+		const std::string unusable_postfix = "(modified)";
 		for (size_t i = 0; i < std::strlen(unusable_symbols); i++){
 			if (m_chosen_name.find_first_of(unusable_symbols[i]) != std::string::npos){
 				is_unusable_symbol = true;
 				break;
 			}
 		}
+		if (m_chosen_name.find(unusable_postfix) != std::string::npos)
+			is_unusable_postfix = true;
+
 		if (is_unusable_symbol) {
-			show_error(this, _(L("The supplied name is not valid; the following characters are not allowed:"))+" <>:/\\|?*\"");
+			show_error(this,_(L("The supplied name is not valid;")) + "\n" +
+							_(L("the following characters are not allowed:")) + " <>:/\\|?*\"");
+		}
+		else if (is_unusable_postfix){
+			show_error(this,	_(L("The supplied name is not valid;")) + "\n" + 
+								_(L("the following postfix are not allowed:")) + "\n\t" + unusable_postfix);
 		}
 		else if (m_chosen_name.compare("- default -") == 0) {
 			show_error(this, _(L("The supplied name is not available.")));
diff --git a/xs/src/slic3r/Utils/Http.cpp b/xs/src/slic3r/Utils/Http.cpp
index 0826284d8..47021d39f 100644
--- a/xs/src/slic3r/Utils/Http.cpp
+++ b/xs/src/slic3r/Utils/Http.cpp
@@ -3,13 +3,16 @@
 #include <cstdlib>
 #include <functional>
 #include <thread>
-#include <tuple>
+#include <deque>
+#include <boost/filesystem/fstream.hpp>
 #include <boost/format.hpp>
 
 #include <curl/curl.h>
 
 #include "../../libslic3r/libslic3r.h"
 
+namespace fs = boost::filesystem;
+
 
 namespace Slic3r {
 
@@ -34,7 +37,11 @@ struct Http::priv
 	::curl_httppost *form;
 	::curl_httppost *form_end;
 	::curl_slist *headerlist;
+	// Used for reading the body
 	std::string buffer;
+	// Used for storing file streams added as multipart form parts
+	// Using a deque here because unlike vector it doesn't ivalidate pointers on insertion
+	std::deque<fs::ifstream> form_files;
 	size_t limit;
 	bool cancel;
 
@@ -50,6 +57,10 @@ struct Http::priv
 	static size_t writecb(void *data, size_t size, size_t nmemb, void *userp);
 	static int xfercb(void *userp, curl_off_t dltotal, curl_off_t dlnow, curl_off_t ultotal, curl_off_t ulnow);
 	static int xfercb_legacy(void *userp, double dltotal, double dlnow, double ultotal, double ulnow);
+	static size_t form_file_read_cb(char *buffer, size_t size, size_t nitems, void *userp);
+
+	void form_add_file(const char *name, const fs::path &path, const char* filename);
+
 	std::string curl_error(CURLcode curlcode);
 	std::string body_size_error();
 	void http_perform();
@@ -135,6 +146,46 @@ int Http::priv::xfercb_legacy(void *userp, double dltotal, double dlnow, double
 	return xfercb(userp, dltotal, dlnow, ultotal, ulnow);
 }
 
+size_t Http::priv::form_file_read_cb(char *buffer, size_t size, size_t nitems, void *userp)
+{
+	auto stream = reinterpret_cast<fs::ifstream*>(userp);
+
+	try {
+		stream->read(buffer, size * nitems);
+	} catch (...) {
+		return CURL_READFUNC_ABORT;
+	}
+
+	return stream->gcount();
+}
+
+void Http::priv::form_add_file(const char *name, const fs::path &path, const char* filename)
+{
+	// We can't use CURLFORM_FILECONTENT, because curl doesn't support Unicode filenames on Windows
+	// and so we use CURLFORM_STREAM with boost ifstream to read the file.
+
+	if (filename == nullptr) {
+		filename = path.string().c_str();
+	}
+
+	form_files.emplace_back(path, std::ios::in | std::ios::binary);
+	auto &stream = form_files.back();
+	stream.seekg(0, std::ios::end);
+	size_t size = stream.tellg();
+	stream.seekg(0);
+
+	if (filename != nullptr) {
+		::curl_formadd(&form, &form_end,
+			CURLFORM_COPYNAME, name,
+			CURLFORM_FILENAME, filename,
+			CURLFORM_CONTENTTYPE, "application/octet-stream",
+			CURLFORM_STREAM, static_cast<void*>(&stream),
+			CURLFORM_CONTENTSLENGTH, static_cast<long>(size),
+			CURLFORM_END
+		);
+	}
+}
+
 std::string Http::priv::curl_error(CURLcode curlcode)
 {
 	return (boost::format("%1% (%2%)")
@@ -154,6 +205,7 @@ void Http::priv::http_perform()
 	::curl_easy_setopt(curl, CURLOPT_FOLLOWLOCATION, 1L);
 	::curl_easy_setopt(curl, CURLOPT_WRITEFUNCTION, writecb);
 	::curl_easy_setopt(curl, CURLOPT_WRITEDATA, static_cast<void*>(this));
+	::curl_easy_setopt(curl, CURLOPT_READFUNCTION, form_file_read_cb);
 
 	::curl_easy_setopt(curl, CURLOPT_NOPROGRESS, 0L);
 #if LIBCURL_VERSION_MAJOR >= 7 && LIBCURL_VERSION_MINOR >= 32
@@ -183,14 +235,20 @@ void Http::priv::http_perform()
 
 	if (res != CURLE_OK) {
 		if (res == CURLE_ABORTED_BY_CALLBACK) {
-			Progress dummyprogress(0, 0, 0, 0);
-			bool cancel = true;
-			if (progressfn) { progressfn(dummyprogress, cancel); }
+			if (cancel) {
+				// The abort comes from the request being cancelled programatically
+				Progress dummyprogress(0, 0, 0, 0);
+				bool cancel = true;
+				if (progressfn) { progressfn(dummyprogress, cancel); }
+			} else {
+				// The abort comes from the CURLOPT_READFUNCTION callback, which means reading file failed
+				if (errorfn) { errorfn(std::move(buffer), "Error reading file for file upload", http_status); }
+			}
 		}
 		else if (res == CURLE_WRITE_ERROR) {
-			if (errorfn) { errorfn(std::move(buffer), std::move(body_size_error()), http_status); }
+			if (errorfn) { errorfn(std::move(buffer), body_size_error(), http_status); }
 		} else {
-			if (errorfn) { errorfn(std::move(buffer), std::move(curl_error(res)), http_status); }
+			if (errorfn) { errorfn(std::move(buffer), curl_error(res), http_status); }
 		};
 	} else {
 		if (completefn) {
@@ -265,17 +323,15 @@ Http& Http::form_add(const std::string &name, const std::string &contents)
 	return *this;
 }
 
-Http& Http::form_add_file(const std::string &name, const std::string &filename)
+Http& Http::form_add_file(const std::string &name, const fs::path &path)
 {
-	if (p) {
-		::curl_formadd(&p->form, &p->form_end,
-			CURLFORM_COPYNAME, name.c_str(),
-			CURLFORM_FILE, filename.c_str(),
-			CURLFORM_CONTENTTYPE, "application/octet-stream",
-			CURLFORM_END
-		);
-	}
+	if (p) { p->form_add_file(name.c_str(), path.c_str(), nullptr); }
+	return *this;
+}
 
+Http& Http::form_add_file(const std::string &name, const fs::path &path, const std::string &filename)
+{
+	if (p) { p->form_add_file(name.c_str(), path.c_str(), filename.c_str()); }
 	return *this;
 }
 
diff --git a/xs/src/slic3r/Utils/Http.hpp b/xs/src/slic3r/Utils/Http.hpp
index 7ed8196e6..73656bf88 100644
--- a/xs/src/slic3r/Utils/Http.hpp
+++ b/xs/src/slic3r/Utils/Http.hpp
@@ -4,6 +4,7 @@
 #include <memory>
 #include <string>
 #include <functional>
+#include <boost/filesystem/path.hpp>
 
 
 namespace Slic3r {
@@ -16,11 +17,11 @@ private:
 public:
 	struct Progress
 	{
-		size_t dltotal;
-		size_t dlnow;
-		size_t ultotal;
-		size_t ulnow;
-		
+		size_t dltotal;   // Total bytes to download
+		size_t dlnow;     // Bytes downloaded so far
+		size_t ultotal;   // Total bytes to upload
+		size_t ulnow;     // Bytes uploaded so far
+
 		Progress(size_t dltotal, size_t dlnow, size_t ultotal, size_t ulnow) :
 			dltotal(dltotal), dlnow(dlnow), ultotal(ultotal), ulnow(ulnow)
 		{}
@@ -33,6 +34,10 @@ public:
 
 	Http(Http &&other);
 
+	// Note: strings are expected to be UTF-8-encoded
+
+	// These are the primary constructors that create a HTTP object
+	// for a GET and a POST request respectively.
 	static Http get(std::string url);
 	static Http post(std::string url);
 	~Http();
@@ -41,21 +46,42 @@ public:
 	Http& operator=(const Http &) = delete;
 	Http& operator=(Http &&) = delete;
 
+	// Sets a maximum size of the data that can be received. The default is 5MB.
 	Http& size_limit(size_t sizeLimit);
+	// Sets a HTTP header field.
 	Http& header(std::string name, const std::string &value);
+	// Removes a header field.
 	Http& remove_header(std::string name);
+	// Sets a CA certificate file for usage with HTTPS. This is only supported on some backends,
+	// specifically, this is supported with OpenSSL and NOT supported with Windows and OS X native certificate store.
+	// See also ca_file_supported().
 	Http& ca_file(const std::string &filename);
+	// Add a HTTP multipart form field
 	Http& form_add(const std::string &name, const std::string &contents);
-	Http& form_add_file(const std::string &name, const std::string &filename);
+	// Add a HTTP multipart form file data contents, `name` is the name of the part
+	Http& form_add_file(const std::string &name, const boost::filesystem::path &path);
+	// Same as above except also override the file's filename with a custom one
+	Http& form_add_file(const std::string &name, const boost::filesystem::path &path, const std::string &filename);
 
+	// Callback called on HTTP request complete
 	Http& on_complete(CompleteFn fn);
+	// Callback called on an error occuring at any stage of the requests: Url parsing, DNS lookup,
+	// TCP connection, HTTP transfer, and finally also when the response indicates an error (status >= 400).
+	// Therefore, a response body may or may not be present.
 	Http& on_error(ErrorFn fn);
+	// Callback called on data download/upload prorgess (called fairly frequently).
+	// See the `Progress` structure for description of the data passed.
+	// Writing a true-ish value into the cancel reference parameter cancels the request.
 	Http& on_progress(ProgressFn fn);
 
+	// Starts performing the request in a background thread
 	Ptr perform();
+	// Starts performing the request on the current thread
 	void perform_sync();
+	// Cancels a request in progress
 	void cancel();
 
+	// Tells whether current backend supports seting up a CA file using ca_file()
 	static bool ca_file_supported();
 private:
 	Http(const std::string &url);
diff --git a/xs/src/slic3r/Utils/OctoPrint.cpp b/xs/src/slic3r/Utils/OctoPrint.cpp
index e63a16c38..86049de16 100644
--- a/xs/src/slic3r/Utils/OctoPrint.cpp
+++ b/xs/src/slic3r/Utils/OctoPrint.cpp
@@ -1,20 +1,65 @@
 #include "OctoPrint.hpp"
 
 #include <algorithm>
+#include <boost/filesystem/path.hpp>
 #include <boost/format.hpp>
+#include <boost/log/trivial.hpp>
 
 #include <wx/frame.h>
 #include <wx/event.h>
 #include <wx/progdlg.h>
+#include <wx/sizer.h>
+#include <wx/stattext.h>
+#include <wx/textctrl.h>
+#include <wx/checkbox.h>
 
 #include "libslic3r/PrintConfig.hpp"
 #include "slic3r/GUI/GUI.hpp"
+#include "slic3r/GUI/MsgDialog.hpp"
 #include "Http.hpp"
 
+namespace fs = boost::filesystem;
+
 
 namespace Slic3r {
 
 
+struct SendDialog : public GUI::MsgDialog
+{
+	wxTextCtrl *txt_filename;
+	wxCheckBox *box_print;
+
+	SendDialog(const fs::path &path) :
+		MsgDialog(nullptr, _(L("Send G-Code to printer")), _(L("Upload to OctoPrint with the following filename:")), wxID_NONE),
+		txt_filename(new wxTextCtrl(this, wxID_ANY, path.filename().wstring())),
+		box_print(new wxCheckBox(this, wxID_ANY, _(L("Start printing after upload"))))
+	{
+		auto *label_dir_hint = new wxStaticText(this, wxID_ANY, _(L("Use forward slashes ( / ) as a directory separator if needed.")));
+		label_dir_hint->Wrap(CONTENT_WIDTH);
+
+		content_sizer->Add(txt_filename, 0, wxEXPAND);
+		content_sizer->Add(label_dir_hint);
+		content_sizer->AddSpacer(VERT_SPACING);
+		content_sizer->Add(box_print, 0, wxBOTTOM, 2*VERT_SPACING);
+
+		btn_sizer->Add(CreateStdDialogButtonSizer(wxOK | wxCANCEL));
+
+		txt_filename->SetFocus();
+		wxString stem(path.stem().wstring());
+		txt_filename->SetSelection(0, stem.Length());
+
+		Fit();
+	}
+
+	fs::path filename() const {
+		return fs::path(txt_filename->GetValue().wx_str());
+	}
+
+	bool print() const { return box_print->GetValue(); }
+};
+
+
+
 OctoPrint::OctoPrint(DynamicPrintConfig *config) :
 	host(config->opt_string("octoprint_host")),
 	apikey(config->opt_string("octoprint_apikey")),
@@ -27,24 +72,39 @@ bool OctoPrint::test(wxString &msg) const
 	// it is ok to refer to `msg` from within the closure
 
 	bool res = true;
+	auto url = make_url("api/version");
+
+	BOOST_LOG_TRIVIAL(info) << boost::format("Octoprint: Get version at: %1%") % url;
 
-	auto url = std::move(make_url("api/version"));
 	auto http = Http::get(std::move(url));
 	set_auth(http);
 	http.on_error([&](std::string, std::string error, unsigned status) {
+			BOOST_LOG_TRIVIAL(error) << boost::format("Octoprint: Error getting version: %1% (HTTP %2%)") % error % status;
 			res = false;
 			msg = format_error(error, status);
 		})
+		.on_complete([&](std::string body, unsigned) {
+			BOOST_LOG_TRIVIAL(debug) << boost::format("Octoprint: Got version: %1%") % body;
+		})
 		.perform_sync();
 
 	return res;
 }
 
-bool OctoPrint::send_gcode(const std::string &filename, bool print) const
+bool OctoPrint::send_gcode(const std::string &filename) const
 {
 	enum { PROGRESS_RANGE = 1000 };
 
 	const auto errortitle = _(L("Error while uploading to the OctoPrint server"));
+	fs::path filepath(filename);
+
+	SendDialog send_dialog(filepath.filename());
+	if (send_dialog.ShowModal() != wxID_OK) { return false; }
+
+	const bool print = send_dialog.print();
+	const auto upload_filepath = send_dialog.filename();
+	const auto upload_filename = upload_filepath.filename();
+	const auto upload_parent_path = upload_filepath.parent_path();
 
 	wxProgressDialog progress_dialog(
 		_(L("OctoPrint upload")),
@@ -61,14 +121,26 @@ bool OctoPrint::send_gcode(const std::string &filename, bool print) const
 
 	bool res = true;
 
-	auto http = Http::post(std::move(make_url("api/files/local")));
+	auto url = make_url("api/files/local");
+
+	BOOST_LOG_TRIVIAL(info) << boost::format("Octoprint: Uploading file %1% at %2%, filename: %3%, path: %4%, print: %5%")
+		% filepath.string()
+		% url
+		% upload_filename.string()
+		% upload_parent_path.string()
+		% print;
+
+	auto http = Http::post(std::move(url));
 	set_auth(http);
 	http.form_add("print", print ? "true" : "false")
-		.form_add_file("file", filename)
+		.form_add("path", upload_parent_path.string())
+		.form_add_file("file", filename, upload_filename.string())
 		.on_complete([&](std::string body, unsigned status) {
+			BOOST_LOG_TRIVIAL(debug) << boost::format("Octoprint: File uploaded: HTTP %1%: %2%") % status % body;
 			progress_dialog.Update(PROGRESS_RANGE);
 		})
 		.on_error([&](std::string body, std::string error, unsigned status) {
+			BOOST_LOG_TRIVIAL(error) << boost::format("Octoprint: Error uploading file: %1% (HTTP %2%)") % error % status;
 			auto errormsg = wxString::Format("%s: %s", errortitle, format_error(error, status));
 			GUI::show_error(&progress_dialog, std::move(errormsg));
 			res = false;
@@ -102,24 +174,24 @@ std::string OctoPrint::make_url(const std::string &path) const
 {
 	if (host.find("http://") == 0 || host.find("https://") == 0) {
 		if (host.back() == '/') {
-			return std::move((boost::format("%1%%2%") % host % path).str());
+			return (boost::format("%1%%2%") % host % path).str();
 		} else {
-			return std::move((boost::format("%1%/%2%") % host % path).str());
+			return (boost::format("%1%/%2%") % host % path).str();
 		}
 	} else {
-		return std::move((boost::format("http://%1%/%2%") % host % path).str());
+		return (boost::format("http://%1%/%2%") % host % path).str();
 	}
 }
 
-wxString OctoPrint::format_error(std::string error, unsigned status)
+wxString OctoPrint::format_error(const std::string &error, unsigned status)
 {
-	const wxString wxerror = error;
+	auto wxerror = wxString::FromUTF8(error.data());
 
 	if (status != 0) {
 		return wxString::Format("HTTP %u: %s", status,
 			(status == 401 ? _(L("Invalid API key")) : wxerror));
 	} else {
-		return std::move(wxerror);
+		return wxerror;
 	}
 }
 
diff --git a/xs/src/slic3r/Utils/OctoPrint.hpp b/xs/src/slic3r/Utils/OctoPrint.hpp
index 744b4fcc1..a8599faa9 100644
--- a/xs/src/slic3r/Utils/OctoPrint.hpp
+++ b/xs/src/slic3r/Utils/OctoPrint.hpp
@@ -17,7 +17,8 @@ public:
 	OctoPrint(DynamicPrintConfig *config);
 
 	bool test(wxString &curl_msg) const;
-	bool send_gcode(const std::string &filename, bool print = false) const;
+	// Send gcode file to octoprint, filename is expected to be in UTF-8
+	bool send_gcode(const std::string &filename) const;
 private:
 	std::string host;
 	std::string apikey;
@@ -25,7 +26,7 @@ private:
 
 	void set_auth(Http &http) const;
 	std::string make_url(const std::string &path) const;
-	static wxString format_error(std::string error, unsigned status);
+	static wxString format_error(const std::string &error, unsigned status);
 };
 
 
diff --git a/xs/xsp/GUI_3DScene.xsp b/xs/xsp/GUI_3DScene.xsp
index 29f35293b..8ee88543d 100644
--- a/xs/xsp/GUI_3DScene.xsp
+++ b/xs/xsp/GUI_3DScene.xsp
@@ -190,6 +190,11 @@ remove_all_canvases()
     CODE:
         _3DScene::remove_all_canvases();
 
+void
+reset_current_canvas()
+    CODE:
+        _3DScene::reset_current_canvas();
+
 void
 set_active(canvas, active)
         SV   *canvas;
@@ -197,6 +202,12 @@ set_active(canvas, active)
     CODE:
         _3DScene::set_active((wxGLCanvas*)wxPli_sv_2_object(aTHX_ canvas, "Wx::GLCanvas"), active);
 
+void
+set_as_dirty(canvas)
+        SV *canvas;
+    CODE:
+        _3DScene::set_as_dirty((wxGLCanvas*)wxPli_sv_2_object(aTHX_ canvas, "Wx::GLCanvas"));
+
 unsigned int
 get_volumes_count(canvas)
         SV *canvas;
diff --git a/xs/xsp/Utils_OctoPrint.xsp b/xs/xsp/Utils_OctoPrint.xsp
index 282a3055d..28610cb01 100644
--- a/xs/xsp/Utils_OctoPrint.xsp
+++ b/xs/xsp/Utils_OctoPrint.xsp
@@ -9,5 +9,5 @@
     OctoPrint(DynamicPrintConfig *config);
     ~OctoPrint();
 
-    bool send_gcode(std::string filename, bool print = false) const;
+    bool send_gcode(std::string filename) const;
 };