.sack(), following error is thrown:To register this class use: kryo.register, but I can't find any documentation on how to do this for over a day now. Can you please provide me a hint in the right direction?GraphBinaryMessageSerializer. The format for GraphBinary custom objects is shown here: https://tinkerpop.apache.org/docs/current/dev/io/#_custom There are tests that show how to create a custom serializer and how to configure it here: https://github.com/apache/tinkerpop/blob/3.5.5/gremlin-driver/src/test/java/org/apache/tinkerpop/gremlin/driver/ser/binary/types/sample/SamplePersonSerializerTest.java I hope it's clear that the code based configuration performed in the tests could just as well be done in the the yaml config files.