diff --git a/src/libslic3r/GCode/CoolingBuffer.cpp b/src/libslic3r/GCode/CoolingBuffer.cpp
index b574c95b37..41655a754d 100644
--- a/src/libslic3r/GCode/CoolingBuffer.cpp
+++ b/src/libslic3r/GCode/CoolingBuffer.cpp
@@ -783,8 +783,8 @@ std::string CoolingBuffer::apply_layer_cooldown(
             if (int(layer_id) >= disable_fan_first_layers && int(layer_id) + 1 < full_fan_speed_layer) {
                 // Ramp up the fan speed from disable_fan_first_layers to full_fan_speed_layer.
                 float factor = float(int(layer_id + 1) - disable_fan_first_layers) / float(full_fan_speed_layer - disable_fan_first_layers);
-                fan_speed_new    = std::clamp(int(float(fan_speed_new) * factor + 0.5f), 0, 255);
-                bridge_fan_speed = std::clamp(int(float(bridge_fan_speed) * factor + 0.5f), 0, 255);
+                fan_speed_new    = std::clamp(int(float(fan_speed_new) * factor + 0.5f), 0, 100);
+                bridge_fan_speed = std::clamp(int(float(bridge_fan_speed) * factor + 0.5f), 0, 100);
                 custom_fan_speed_limits.second = fan_speed_new;
             }
 #undef EXTRUDER_CONFIG
diff --git a/src/libslic3r/GCode/ToolOrdering.cpp b/src/libslic3r/GCode/ToolOrdering.cpp
index acddb137e5..acc3bf2050 100644
--- a/src/libslic3r/GCode/ToolOrdering.cpp
+++ b/src/libslic3r/GCode/ToolOrdering.cpp
@@ -470,20 +470,16 @@ void ToolOrdering::fill_wipe_tower_partitions(const PrintConfig &config, coordf_
 bool ToolOrdering::insert_wipe_tower_extruder()
 {
     // In case that wipe_tower_extruder is set to non-zero, we must make sure that the extruder will be in the list.
+    // The list is 1-based, as is the config value !
     bool changed = false;
     if (m_print_config_ptr->wipe_tower_extruder != 0) {
         for (LayerTools& lt : m_layer_tools) {
             if (lt.wipe_tower_partitions > 0) {
-                lt.extruders.emplace_back(m_print_config_ptr->wipe_tower_extruder - 1);
+                lt.extruders.emplace_back(m_print_config_ptr->wipe_tower_extruder);
                 sort_remove_duplicates(lt.extruders);
                 changed = true;
             }
         }
-        // Now convert the 0-based list to 1-based again.
-        for (LayerTools& lt : m_layer_tools) {
-            for (auto& extruder : lt.extruders)
-                    ++extruder;
-        }
     }
     return changed;
 }
diff --git a/src/slic3r/GUI/GUI_ObjectLayers.cpp b/src/slic3r/GUI/GUI_ObjectLayers.cpp
index 6f6ec52380..4727c6d30b 100644
--- a/src/slic3r/GUI/GUI_ObjectLayers.cpp
+++ b/src/slic3r/GUI/GUI_ObjectLayers.cpp
@@ -283,7 +283,7 @@ void ObjectLayers::sys_color_changed()
         if (item->IsSizer()) {// case when we have editor with buttons
             for (size_t btn : {2, 3}) { // del_btn, add_btn
                 wxSizerItem* b_item = item->GetSizer()->GetItem(btn);
-                if (b_item->IsWindow()) {
+                if (b_item && b_item->IsWindow()) {
                     auto button = dynamic_cast<PlusMinusButton*>(b_item->GetWindow());
                     if (button != nullptr)
                         button->sys_color_changed();