diff --git a/src/libslic3r/PrintConfig.cpp b/src/libslic3r/PrintConfig.cpp
index 04c886963..9684bc672 100644
--- a/src/libslic3r/PrintConfig.cpp
+++ b/src/libslic3r/PrintConfig.cpp
@@ -85,6 +85,8 @@ void PrintConfigDef::init_common_params()
     def->label = L("Max print height");
     def->tooltip = L("Set this to the maximum height that can be reached by your extruder while printing.");
     def->sidetext = L("mm");
+    def->min = 0;
+    def->max = 1200;
     def->mode = comAdvanced;
     def->set_default_value(new ConfigOptionFloat(200.0));
 
diff --git a/src/slic3r/GUI/GUI_App.cpp b/src/slic3r/GUI/GUI_App.cpp
index 3c000f62e..9dfb4b422 100644
--- a/src/slic3r/GUI/GUI_App.cpp
+++ b/src/slic3r/GUI/GUI_App.cpp
@@ -715,16 +715,24 @@ void GUI_App::update_ui_from_settings()
 void GUI_App::persist_window_geometry(wxTopLevelWindow *window, bool default_maximized)
 {
     const std::string name = into_u8(window->GetName());
+    wxTopLevelWindow* settings_dlg = dynamic_cast<MainFrame*>(window)->m_settings_dialog;
+    const std::string settings_dlg_name = "settings_dialog";
 
     window->Bind(wxEVT_CLOSE_WINDOW, [=](wxCloseEvent &event) {
         window_pos_save(window, name);
+        if (settings_dlg)
+            window_pos_save(settings_dlg, settings_dlg_name);
         event.Skip();
     });
 
     window_pos_restore(window, name, default_maximized);
+    if (settings_dlg)
+        window_pos_restore(settings_dlg, settings_dlg_name, default_maximized);
 
     on_window_geometry(window, [=]() {
         window_pos_sanitize(window);
+        if (settings_dlg)
+            window_pos_sanitize(settings_dlg);
     });
 }
 
diff --git a/src/slic3r/GUI/GUI_ObjectList.cpp b/src/slic3r/GUI/GUI_ObjectList.cpp
index d5e05ce1f..441f30816 100644
--- a/src/slic3r/GUI/GUI_ObjectList.cpp
+++ b/src/slic3r/GUI/GUI_ObjectList.cpp
@@ -2696,6 +2696,9 @@ bool ObjectList::can_split_instances()
 
 bool ObjectList::can_merge_to_multipart_object() const
 {
+    if (printer_technology() == ptSLA)
+        return false;
+
     wxDataViewItemArray sels;
     GetSelections(sels);
     if (sels.IsEmpty())
diff --git a/src/slic3r/GUI/Gizmos/GLGizmoFdmSupports.cpp b/src/slic3r/GUI/Gizmos/GLGizmoFdmSupports.cpp
index 97e2ffed2..da5695397 100644
--- a/src/slic3r/GUI/Gizmos/GLGizmoFdmSupports.cpp
+++ b/src/slic3r/GUI/Gizmos/GLGizmoFdmSupports.cpp
@@ -365,13 +365,23 @@ bool GLGizmoFdmSupports::gizmo_event(SLAGizmoEventType action, const Vec2d& mous
             }
         }
 
+        bool dragging_while_painting = (action == SLAGizmoEventType::Dragging && m_button_down != Button::None);
+
+        // The mouse button click detection is enabled when there is a valid hit
+        // or when the user clicks the clipping plane. Missing the object entirely
+        // shall not capture the mouse.
+        if (closest_hit_mesh_id != -1 || clipped_mesh_was_hit) {
+            if (m_button_down == Button::None)
+                m_button_down = ((action == SLAGizmoEventType::LeftDown) ? Button::Left : Button::Right);
+        }
+
         if (closest_hit_mesh_id == -1) {
             // In case we have no valid hit, we can return. The event will
             // be stopped in following two cases:
             //  1. clicking the clipping plane
             //  2. dragging while painting (to prevent scene rotations and moving the object)
             return clipped_mesh_was_hit
-                || (action == SLAGizmoEventType::Dragging && m_button_down != Button::None);
+                || dragging_while_painting;
         }
 
         // Now propagate the hits
@@ -472,10 +482,6 @@ bool GLGizmoFdmSupports::gizmo_event(SLAGizmoEventType action, const Vec2d& mous
             }
         }
 
-
-        if (m_button_down == Button::None)
-            m_button_down = ((action == SLAGizmoEventType::LeftDown) ? Button::Left : Button::Right);
-
         return true;
     }
 
diff --git a/src/slic3r/GUI/MainFrame.cpp b/src/slic3r/GUI/MainFrame.cpp
index d8a799eb2..d35b397a6 100644
--- a/src/slic3r/GUI/MainFrame.cpp
+++ b/src/slic3r/GUI/MainFrame.cpp
@@ -204,29 +204,6 @@ DPIFrame(NULL, wxID_ANY, "", wxDefaultPosition, wxDefaultSize, wxDEFAULT_FRAME_S
         event.Skip();
     });
 
-    /*
-    Bind(wxEVT_SYS_COLOUR_CHANGED, [this](wxSysColourChangedEvent& event)
-    {
-        bool recreate_gui = false;
-        {
-            // the dialog needs to be destroyed before the call to recreate_gui()
-            // or sometimes the application crashes into wxDialogBase() destructor
-            // so we put it into an inner scope
-            wxMessageDialog dialog(nullptr,
-                                   _L("System color mode was changed. "
-                                      "It is possible to update the Slicer in respect to the system mode.") + "\n" +
-                                   _L("You will lose content of the plater.") + "\n\n" +
-                                   _L("Do you want to proceed?"),
-                                   wxString(SLIC3R_APP_NAME) + " - " + _L("Switching system color mode"),
-                                   wxICON_QUESTION | wxOK | wxCANCEL);
-            recreate_gui = dialog.ShowModal() == wxID_OK;
-        }
-        if (recreate_gui)
-            wxGetApp().recreate_GUI(_L("Changing of an application in respect to the system mode") + dots);
-        event.Skip();
-    });
-    */
-
     wxGetApp().persist_window_geometry(this, true);
 
     update_ui_from_settings();    // FIXME (?)
@@ -350,7 +327,8 @@ void MainFrame::init_tabpanel()
     m_tabpanel->Bind(wxEVT_NOTEBOOK_PAGE_CHANGED, [this](wxEvent&) {
         auto panel = m_tabpanel->GetCurrentPage();
 
-        if (panel == nullptr)
+        // There shouldn't be a case, when we try to select a tab, which doesn't support a printer technology
+        if (panel == nullptr || !static_cast<Tab*>(panel)->supports_printer_technology(m_plater->printer_technology()))
             return;
 
         auto& tabs_list = wxGetApp().tabs_list;