Fix #1288 - error when importing consecutive files.

src/ifcblenderexport/blenderbim/bim/handler.py

@@ -15,6 +15,16 @@ def loadIfcStore(scene):
         {k: bpy.data.objects.get(v) for k, v in json.loads(props.guid_map).items()} if props.id_map else {}
     )
 
+    # Purge data cache
+    from blenderbim.bim import modules
+    for module in modules.values():
+        if not module:
+            continue
+        try:
+            getattr(getattr(module, 'data'), 'Data').purge()
+        except AttributeError:
+            pass
+
 
 @persistent
 def storeIdMap(scene):