I'm having the same issue and I don't understand the explanations. I'm using Flink 1.9.3 and a KeyedCoProcessFunction. My state's class is still being used (it's a POJO), but I removed one of its fields. According to the documentation <https://ci.apache.org/projects/flink/flink-docs-release-1.9/dev/stream/state/schema_evolution.html#supported-data-types-for-schema-evolution> , this should be supported. The example <https://ci.apache.org/projects/flink/flink-docs-release-1.9/dev/stream/operators/process_function.html#example> shows getRuntimeContext().getState() being used in the open() method, and that's what I do as well.
I get the exact same null pointer exception. If "once the state is registered, it cannot be removed anymore", then why does the documentation state otherwise? Regards, Alexis. -- Sent from: http://apache-flink-user-mailing-list-archive.2336050.n4.nabble.com/
