diff --git a/cura/Settings/MachineManager.py b/cura/Settings/MachineManager.py index 4ff5ad95cd..a16fd0d18d 100755 --- a/cura/Settings/MachineManager.py +++ b/cura/Settings/MachineManager.py @@ -1305,9 +1305,10 @@ class MachineManager(QObject): self._setMaterial(position_item, new_material) else: # The current material is not available, find the preferred one. - approximate_material_diameter = int(self._global_container_stack.extruderList[int(position)].getApproximateMaterialDiameter()) - material_node = nozzle_node.preferredMaterial(approximate_material_diameter) - self._setMaterial(position_item, material_node) + if position is not None: + approximate_material_diameter = int(self._global_container_stack.extruderList[int(position)].getApproximateMaterialDiameter()) + material_node = nozzle_node.preferredMaterial(approximate_material_diameter) + self._setMaterial(position_item, material_node) ## Given a printer definition name, select the right machine instance. In case it doesn't exist, create a new # instance with the same network key.