Checkpointing in portable pipelines does not work

AsynchronousException{java.lang.Exception: Could not materialize checkpoint 2 for operator Source: Custom Source -> 9TestInput.None/beam:env:docker:v1:0 -> ToKeyedWorkItem (1/1).}
	at org.apache.flink.streaming.runtime.tasks.StreamTask$AsyncCheckpointExceptionHandler.tryHandleCheckpointException(StreamTask.java:1154)
	at org.apache.flink.streaming.runtime.tasks.StreamTask$AsyncCheckpointRunnable.handleExecutionException(StreamTask.java:948)
	at org.apache.flink.streaming.runtime.tasks.StreamTask$AsyncCheckpointRunnable.run(StreamTask.java:885)
	at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511)
	at java.util.concurrent.FutureTask.run(FutureTask.java:266)
	at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)
	at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
	at java.lang.Thread.run(Thread.java:748)
Caused by: java.lang.Exception: Could not materialize checkpoint 2 for operator Source: Custom Source -> 9TestInput.None/beam:env:docker:v1:0 -> ToKeyedWorkItem (1/1).
	at org.apache.flink.streaming.runtime.tasks.StreamTask$AsyncCheckpointRunnable.handleExecutionException(StreamTask.java:943)
	... 6 more
Caused by: java.util.concurrent.ExecutionException: java.lang.NullPointerException
	at java.util.concurrent.FutureTask.report(FutureTask.java:122)
	at java.util.concurrent.FutureTask.get(FutureTask.java:192)
	at org.apache.flink.util.FutureUtil.runIfNotDoneAndGet(FutureUtil.java:53)
	at org.apache.flink.streaming.api.operators.OperatorSnapshotFinalizer.<init>(OperatorSnapshotFinalizer.java:53)
	at org.apache.flink.streaming.runtime.tasks.StreamTask$AsyncCheckpointRunnable.run(StreamTask.java:854)
	... 5 more
Caused by: java.lang.NullPointerException
	at org.apache.beam.runners.flink.translation.types.CoderTypeSerializer$CoderTypeSerializerConfigSnapshot.<init>(CoderTypeSerializer.java:162)
	at org.apache.beam.runners.flink.translation.types.CoderTypeSerializer.snapshotConfiguration(CoderTypeSerializer.java:136)
	at org.apache.flink.runtime.state.RegisteredOperatorBackendStateMetaInfo.snapshot(RegisteredOperatorBackendStateMetaInfo.java:93)
	at org.apache.flink.runtime.state.DefaultOperatorStateBackend$1.performOperation(DefaultOperatorStateBackend.java:394)
	at org.apache.flink.runtime.state.DefaultOperatorStateBackend$1.performOperation(DefaultOperatorStateBackend.java:352)
	at org.apache.flink.runtime.io.async.AbstractAsyncCallableWithResources.call(AbstractAsyncCallableWithResources.java:75)
	at java.util.concurrent.FutureTask.run(FutureTask.java:266)
	at org.apache.flink.util.FutureUtil.runIfNotDoneAndGet(FutureUtil.java:50)
	... 7 more