diff --git a/src/libslic3r/GCode.cpp b/src/libslic3r/GCode.cpp
index 011bf3fc4..6ae703a20 100644
--- a/src/libslic3r/GCode.cpp
+++ b/src/libslic3r/GCode.cpp
@@ -1,4 +1,5 @@
 #include "libslic3r.h"
+#include "I18N.hpp"
 #include "GCode.hpp"
 #include "ExtrusionEntity.hpp"
 #include "EdgeGrid.hpp"
@@ -36,6 +37,11 @@
 
 namespace Slic3r {
 
+//! macro used to mark string used at localization,
+//! return same string
+#define L(s) (s)
+#define _(s) Slic3r::I18N::translate(s)
+
 // Only add a newline in case the current G-code does not end with a newline.
 static inline void check_add_eol(std::string &gcode)
 {
@@ -405,7 +411,8 @@ std::string WipeTowerIntegration::tool_change(GCode &gcodegen, int extruder_id,
 	assert(m_layer_idx >= 0 && size_t(m_layer_idx) <= m_tool_changes.size());
     if (! m_brim_done || gcodegen.writer().need_toolchange(extruder_id) || finish_layer) {
 		if (m_layer_idx < (int)m_tool_changes.size()) {
-			assert(size_t(m_tool_change_idx) < m_tool_changes[m_layer_idx].size());
+			if (! (size_t(m_tool_change_idx) < m_tool_changes[m_layer_idx].size()))
+                throw std::runtime_error("Wipe tower generation failed, possibly due to empty first layer.");
 			gcode += append_tcr(gcodegen, m_tool_changes[m_layer_idx][m_tool_change_idx++], extruder_id);
 		}
         m_brim_done = true;
@@ -436,6 +443,14 @@ std::vector<GCode::LayerToPrint> GCode::collect_layers_to_print(const PrintObjec
     size_t idx_object_layer  = 0;
     size_t idx_support_layer = 0;
     while (idx_object_layer < object.layers().size() || idx_support_layer < object.support_layers().size()) {
+        // Let's make sure that the last layer is not empty, so we don't build on top of it.
+        if (! layers_to_print.empty()
+         && (! layers_to_print.back().object_layer  || ! layers_to_print.back().object_layer->has_extrusions())
+         && (! layers_to_print.back().support_layer || ! layers_to_print.back().support_layer->has_extrusions()))
+            throw std::runtime_error(_(L("Empty layers detected, the output would not be printable.")) + "\n\n" +
+                                     _(L("Object name: ")) + object.model_object()->name + "\n" + _(L("Print z: ")) +
+                                     std::to_string(layers_to_print.back().print_z()));
+
         LayerToPrint layer_to_print;
         layer_to_print.object_layer  = (idx_object_layer < object.layers().size()) ? object.layers()[idx_object_layer ++] : nullptr;
         layer_to_print.support_layer = (idx_support_layer < object.support_layers().size()) ? object.support_layers()[idx_support_layer ++] : nullptr;
@@ -448,6 +463,7 @@ std::vector<GCode::LayerToPrint> GCode::collect_layers_to_print(const PrintObjec
                 -- idx_object_layer;
             }
         }
+
         layers_to_print.emplace_back(layer_to_print);
     }
 
diff --git a/src/libslic3r/GCode/ToolOrdering.cpp b/src/libslic3r/GCode/ToolOrdering.cpp
index f10b45723..18437c8e1 100644
--- a/src/libslic3r/GCode/ToolOrdering.cpp
+++ b/src/libslic3r/GCode/ToolOrdering.cpp
@@ -78,8 +78,13 @@ ToolOrdering::ToolOrdering(const Print &print, unsigned int first_extruder, bool
                 zs.emplace_back(layer->print_z);
             for (auto layer : object->support_layers())
                 zs.emplace_back(layer->print_z);
-            if (! object->layers().empty())
-                object_bottom_z = object->layers().front()->print_z - object->layers().front()->height;
+
+            // Find first object layer that is not empty and save its print_z
+            for (const Layer* layer : object->layers())
+                if (layer->has_extrusions()) {
+                    object_bottom_z = layer->print_z - layer->height;
+                    break;
+                }
         }
         this->initialize_layers(zs);
     }
@@ -324,6 +329,7 @@ void ToolOrdering::fill_wipe_tower_partitions(const PrintConfig &config, coordf_
 						m_layer_tools[j].has_wipe_tower = true;
 					} else {
 						LayerTools &lt_extra = *m_layer_tools.insert(m_layer_tools.begin() + j, lt_new);
+                        //LayerTools &lt_prev  = m_layer_tools[j];
                         LayerTools &lt_next  = m_layer_tools[j + 1];
                         assert(! m_layer_tools[j - 1].extruders.empty() && ! lt_next.extruders.empty());
                         // FIXME: Following assert tripped when running combine_infill.t. I decided to comment it out for now.