Knowledge Graph Rag (Community) - Steps Missing

I am trying to run the Community Graph RAG example as mentioned here. But it looks like there are some steps missing between 6 and 7. When I am doing the python server.py as mentioned in Step 7 I am getting the following error

Traceback (most recent call last):
  File "D:\KnowledgeGrpahRAG\GenerativeAIExamples\community\knowledge_graph_rag\backend\server.py", line 18, in <module>
    from routers import ui_backend,chat,evaluation,visualization
  File "D:\KnowledgeGrpahRAG\GenerativeAIExamples\community\knowledge_graph_rag\backend\routers\chat.py", line 42, in <module>
    KG_GRAPHML_PATH = os.path.join(DATA_DIR, "knowledge_graph.graphml")
  File "C:\Users\avish\AppData\Local\Programs\Python\Python310\lib\ntpath.py", line 104, in join
    path = os.fspath(path)
TypeError: expected str, bytes or os.PathLike object, not NoneType

It is looking for knowledge_graph.graphml which possibly is created through some other scripts but not mentioned there. Possibly it will need pre-execution of lc_graph.py under utils folder. Any help to figure out what to do would be appreciated.

Lies die Anweisungen zu Community Graph RAG rund um die Schritte 6 und 7 und untersuche anschließend community/knowledge_graph_rag/backend/server.py sowie die erwähnte utils/lc_graph.py. Dokumentiere den fehlenden erforderlichen Vorbereitungs- oder Generierungsschritt für knowledge_graph.graphml, damit ein Benutzer dem Beispiel folgen und server.py ohne den gemeldeten Fehler starten kann.