diff --git a/src/libslic3r/PresetBundle.cpp b/src/libslic3r/PresetBundle.cpp
index 12b1164b4f..02642ad145 100644
--- a/src/libslic3r/PresetBundle.cpp
+++ b/src/libslic3r/PresetBundle.cpp
@@ -3386,6 +3386,14 @@ std::pair<PresetsConfigSubstitutions, size_t> PresetBundle::load_vendor_configs_
     return std::make_pair(std::move(substitutions), presets_loaded);
 }
 
+void PresetBundle::on_extruders_count_changed(int extruders_count)
+{
+    printers.get_edited_preset().set_num_extruders(extruders_count);
+    update_multi_material_filament_presets();
+    reset_default_nozzle_volume_type();
+    extruder_ams_counts.resize(extruders_count);
+}
+
 void PresetBundle::update_multi_material_filament_presets(size_t to_delete_filament_id)
 {
     if (printers.get_edited_preset().printer_technology() != ptFFF)
diff --git a/src/libslic3r/PresetBundle.hpp b/src/libslic3r/PresetBundle.hpp
index e36bace897..742c6de218 100644
--- a/src/libslic3r/PresetBundle.hpp
+++ b/src/libslic3r/PresetBundle.hpp
@@ -256,6 +256,8 @@ public:
     // update size and content of filament_presets.
     void                        update_multi_material_filament_presets(size_t to_delete_filament_id = size_t(-1));
 
+    void                        on_extruders_count_changed(int extruder_count);
+
     // Update the is_compatible flag of all print and filament presets depending on whether they are marked
     // as compatible with the currently selected printer (and print in case of filament presets).
     // Also updates the is_visible flag of each preset.
diff --git a/src/slic3r/GUI/Plater.cpp b/src/slic3r/GUI/Plater.cpp
index e466631872..1d6c052622 100644
--- a/src/slic3r/GUI/Plater.cpp
+++ b/src/slic3r/GUI/Plater.cpp
@@ -1199,12 +1199,14 @@ void Sidebar::priv::update_sync_status(const MachineObject *obj)
     }
 
     std::vector<std::map<int, int>> extruder_ams_counts = wxGetApp().preset_bundle->extruder_ams_counts;
-    for (size_t i = 0; i < extruder_ams_counts.size(); ++i) {
-        for (auto iter = extruder_ams_counts[i].begin(); iter != extruder_ams_counts[i].end(); ++iter){
-            if (iter->first == 4)
-                extruder_infos[i].ams_4 = iter->second;
-            if (iter->first == 1)
-                extruder_infos[i].ams_1 = iter->second;
+    if (extruder_ams_counts.size() >= extruder_nums) {
+        for (size_t i = 0; i < extruder_nums; ++i) {
+            for (auto iter = extruder_ams_counts[i].begin(); iter != extruder_ams_counts[i].end(); ++iter) {
+                if (iter->first == 4)
+                    extruder_infos[i].ams_4 = iter->second;
+                if (iter->first == 1)
+                    extruder_infos[i].ams_1 = iter->second;
+            }
         }
     }
 
diff --git a/src/slic3r/GUI/Tab.cpp b/src/slic3r/GUI/Tab.cpp
index 4f484168b8..7c64536cec 100644
--- a/src/slic3r/GUI/Tab.cpp
+++ b/src/slic3r/GUI/Tab.cpp
@@ -4278,9 +4278,7 @@ void TabPrinter::extruders_count_changed(size_t extruders_count)
     bool is_count_changed = false;
     if (m_extruders_count != extruders_count) {
         m_extruders_count = extruders_count;
-        m_preset_bundle->printers.get_edited_preset().set_num_extruders(extruders_count);
-        m_preset_bundle->update_multi_material_filament_presets();
-        m_preset_bundle->reset_default_nozzle_volume_type();
+        m_preset_bundle->on_extruders_count_changed(extruders_count);
         is_count_changed = true;
 
         wxGetApp().plater()->get_partplate_list().on_extruder_count_changed((int)m_extruders_count);