diff --git a/xs/src/libslic3r/GCode/WipeTowerPrusaMM.cpp b/xs/src/libslic3r/GCode/WipeTowerPrusaMM.cpp
index 61d8df035..3ef141829 100644
--- a/xs/src/libslic3r/GCode/WipeTowerPrusaMM.cpp
+++ b/xs/src/libslic3r/GCode/WipeTowerPrusaMM.cpp
@@ -643,7 +643,8 @@ WipeTower::ToolChangeResult WipeTowerPrusaMM::tool_change(unsigned int tool, boo
                   "\n\n");
 
     // Ask our writer about how much material was consumed:
-    m_used_filament_length[m_current_tool] += writer.get_and_reset_used_filament_length();
+    if (m_current_tool < m_used_filament_length.size())
+        m_used_filament_length[m_current_tool] += writer.get_and_reset_used_filament_length();
 
 	ToolChangeResult result;
     result.priming      = false;
@@ -1068,8 +1069,9 @@ WipeTower::ToolChangeResult WipeTowerPrusaMM::finish_layer()
 
     m_depth_traversed = m_wipe_tower_depth-m_perimeter_width;
 
-    // Ask our writer about how much material was consumed:
-    m_used_filament_length[m_current_tool] += writer.get_and_reset_used_filament_length();
+    // Ask our writer about how much material was consumed.
+    if (m_current_tool < m_used_filament_length.size())
+        m_used_filament_length[m_current_tool] += writer.get_and_reset_used_filament_length();
 
 	ToolChangeResult result;
     result.priming      = false;
@@ -1166,7 +1168,6 @@ void WipeTowerPrusaMM::save_on_last_wipe()
     }
 }
 
-
 // Processes vector m_plan and calls respective functions to generate G-code for the wipe tower
 // Resulting ToolChangeResults are appended into vector "result"
 void WipeTowerPrusaMM::generate(std::vector<std::vector<WipeTower::ToolChangeResult>> &result)
@@ -1256,6 +1257,4 @@ void WipeTowerPrusaMM::make_wipe_tower_square()
 		lay.extra_spacing = lay.depth / lay.toolchanges_depth();
 }
 
-
-
 }; // namespace Slic3r
diff --git a/xs/src/libslic3r/Model.cpp b/xs/src/libslic3r/Model.cpp
index e0097ce2e..9fe855aa1 100644
--- a/xs/src/libslic3r/Model.cpp
+++ b/xs/src/libslic3r/Model.cpp
@@ -455,10 +455,14 @@ void Model::adjust_min_z()
 unsigned int Model::get_auto_extruder_id(unsigned int max_extruders)
 {
     unsigned int id = s_auto_extruder_id;
-
-    if (++s_auto_extruder_id > max_extruders)
+    if (id > max_extruders) {
+        // The current counter is invalid, likely due to switching the printer profiles
+        // to a profile with a lower number of extruders.
         reset_auto_extruder_id();
-
+        id = s_auto_extruder_id;
+    } else if (++s_auto_extruder_id > max_extruders) {
+        reset_auto_extruder_id();
+    }
     return id;
 }
 
diff --git a/xs/src/libslic3r/libslic3r.h b/xs/src/libslic3r/libslic3r.h
index 4a7898ced..420f1aaa4 100644
--- a/xs/src/libslic3r/libslic3r.h
+++ b/xs/src/libslic3r/libslic3r.h
@@ -14,7 +14,7 @@
 #include <boost/thread.hpp>
 
 #define SLIC3R_FORK_NAME "Slic3r Prusa Edition"
-#define SLIC3R_VERSION "1.41.1"
+#define SLIC3R_VERSION "1.41.2-beta"
 #define SLIC3R_BUILD "UNKNOWN"
 
 typedef int32_t coord_t;
diff --git a/xs/src/slic3r/GUI/GLCanvas3D.cpp b/xs/src/slic3r/GUI/GLCanvas3D.cpp
index 9219a0fa7..b18fc1804 100644
--- a/xs/src/slic3r/GUI/GLCanvas3D.cpp
+++ b/xs/src/slic3r/GUI/GLCanvas3D.cpp
@@ -3436,8 +3436,14 @@ void GLCanvas3D::_refresh_if_shown_on_screen()
     {
         const Size& cnv_size = get_canvas_size();
         _resize((unsigned int)cnv_size.get_width(), (unsigned int)cnv_size.get_height());
-        if (m_canvas != nullptr)
-            m_canvas->Refresh();
+
+        // Because of performance problems on macOS, where PaintEvents are not delivered
+        // frequently enough, we call render() here directly when we can.
+        // We can't do that when m_force_zoom_to_bed_enabled == true, because then render()
+        // ends up calling back here via _force_zoom_to_bed(), causing a stack overflow.
+        if (m_canvas != nullptr) {
+            m_force_zoom_to_bed_enabled ? m_canvas->Refresh() : render();
+        }
     }
 }