Janusgraph upgrade to 1.1.0

After upgrading to Janusgraph 1.1.0, I am started getting below issue

Cannot read the array length because \"elementData\" is null\n\tat java.base/java.util.ArrayList$Itr.next(ArrayList.java:972)\n\tat org.janusgraph.graphdb.database.IndexSerializer.getIndexUpdates(IndexSerializer.java:257)\n\tat org.janusgraph.graphdb.database.IndexSerializer.getIndexUpdates(IndexSerializer.java:206)\n\tat org.janusgraph.graphdb.database.StandardJanusGraph.lambda$prepareCommitVertexIndexUpdates$2(StandardJanusGraph.java:819)\n\tat

I have added below property but its still getting same
storage.num-mutations-parallel-threshold value as 1000 . This is coming on high transaction ..Please suggest

Start with the stack trace in IndexSerializer.getIndexUpdates and StandardJanusGraph.prepareCommitVertexIndexUpdates. Reproduce the failure during a high-volume transaction after upgrading to JanusGraph 1.1.0, then investigate why elementData is null and whether storage.num-mutations-parallel-threshold affects the path. Done means the reported transaction completes without the exception and the relevant regression is covered.

Written by the indexing model from the issue text.