diff --git a/src/admesh/normals.cpp b/src/admesh/normals.cpp
index a8faa44bd..0ad134360 100644
--- a/src/admesh/normals.cpp
+++ b/src/admesh/normals.cpp
@@ -108,6 +108,9 @@ stl_fix_normal_directions(stl_file *stl) {
 
   if (stl->error) return;
 
+  // this may happen for malformed models, see: https://github.com/prusa3d/Slic3r/issues/2209
+  if (stl->stats.number_of_facets == 0) return;
+
   /* Initialize linked list. */
   head = (struct stl_normal*)malloc(sizeof(struct stl_normal));
   if(head == NULL) perror("stl_fix_normal_directions");
diff --git a/src/libslic3r/ModelArrange.cpp b/src/libslic3r/ModelArrange.cpp
index 50901da3a..c821eef77 100644
--- a/src/libslic3r/ModelArrange.cpp
+++ b/src/libslic3r/ModelArrange.cpp
@@ -567,8 +567,13 @@ ShapeData2D projectModelFromTop(const Slic3r::Model &model) {
                 Transform3d trafo_instance = Geometry::assemble_transform(Vec3d::Zero(), rotation, finst->get_scaling_factor(), finst->get_mirror());
                 Polygon p = objptr->convex_hull_2d(trafo_instance);
 				assert(! p.points.empty());
-				p.reverse();
-				assert(! p.is_counter_clockwise());
+
+                // this may happen for malformed models, see: https://github.com/prusa3d/Slic3r/issues/2209
+                if (p.points.empty())
+                    continue;
+
+                p.reverse();
+                assert(!p.is_counter_clockwise());
                 p.append(p.first_point());
                 clpath = Slic3rMultiPoint_to_ClipperPath(p);
             }
diff --git a/src/slic3r/GUI/Gizmos/GLGizmoSlaSupports.cpp b/src/slic3r/GUI/Gizmos/GLGizmoSlaSupports.cpp
index 017c00143..1400bef5e 100644
--- a/src/slic3r/GUI/Gizmos/GLGizmoSlaSupports.cpp
+++ b/src/slic3r/GUI/Gizmos/GLGizmoSlaSupports.cpp
@@ -79,6 +79,8 @@ void GLGizmoSlaSupports::set_sla_support_data(ModelObject* model_object, const S
             m_parent.toggle_model_objects_visibility(false);
             m_parent.toggle_model_objects_visibility(true, m_model_object, m_active_instance);
         }
+        else
+            m_parent.toggle_model_objects_visibility(true, nullptr, -1);
     }
 }
 
diff --git a/src/slic3r/GUI/wxExtensions.cpp b/src/slic3r/GUI/wxExtensions.cpp
index a58881946..7485d6375 100644
--- a/src/slic3r/GUI/wxExtensions.cpp
+++ b/src/slic3r/GUI/wxExtensions.cpp
@@ -57,11 +57,6 @@ wxMenuItem* append_menu_item(wxMenu* menu, int id, const wxString& string, const
     auto *item = new wxMenuItem(menu, id, string, description);
     if (icon.IsOk()) {
         item->SetBitmap(icon);
-#ifndef __WXMSW__
-        wxImage imgGrey = icon.ConvertToImage().ConvertToGreyscale();
-        if (imgGrey.IsOk())
-            item->SetDisabledBitmap(wxBitmap(imgGrey));
-#endif /* __WXMSW__ */
     }
     menu->Append(item);
 
@@ -100,10 +95,6 @@ wxMenuItem* append_submenu(wxMenu* menu, wxMenu* sub_menu, int id, const wxStrin
         item->SetBitmap(create_scaled_bitmap(nullptr, icon));    // FIXME: pass window ptr
 #ifdef __WXMSW__
         msw_menuitem_bitmaps[id] = icon;
-#else /* __WXMSW__ */
-        wxImage imgGrey = icon.ConvertToImage().ConvertToGreyscale();
-        if (imgGrey.IsOk())
-            item->SetDisabledBitmap(wxBitmap(imgGrey));
 #endif /* __WXMSW__ */
     }