fix removing objects with materials after c4ae9578e #4843

temporary fix, we probably should indeed just get rid of that listener

src/blenderbim/blenderbim/bim/module/model/product.py

@@ -526,6 +526,16 @@ def ensure_material_assigned(usecase_path: str, ifc_file: ifcopenshell.file, set
 def ensure_material_unassigned(usecase_path: str, ifc_file: ifcopenshell.file, settings: dict[str, Any]) -> None:
     elements = settings["products"]
 
+    # unassign_material could be called when product is about to get removed
+    # and representation might be already removed.
+    elements = [
+        e
+        for e in elements
+        if (obj := tool.Ifc.get_object(e))
+        and obj.data
+        and tool.Ifc.get_entity_by_id(obj.data.BIMMeshProperties.ifc_definition_id)
+    ]
+
     for element in elements[:]:
         if element.is_a("IfcElementType"):
             elements.extend(tool.Model.get_occurrences_without_material_override(element))