Hi Umesh,

No, it is not clear at all whether the issue and cassandra-4.0 are related, but generally it is not useful to report bugs regarding unsupported configurations. To dig deeper, I would be curious about:
 - can you log the vertex id and label for the transactions that fail and  can you make another transaction fail with these values?
 - the stracktrace suggests that the issue is in querying the graph schema. Can you trigger the exception by manually querying the graph schema for the vertex labels involved?

Best wishes,     Marc