Anthony, I was able to reproduce the issue with a quite simple class https://github.com/claudiu-balciza/GeodeDeserializationErrorPOC/tree/develop
the command line application above populates 3 entries of Class1 objects in the DeserializationErrorPOC region the region is created as follows: gfsh> create region --name=DeserializationErrorPOC --type=PARTITION_REDUNDANT_PERSISTENT --recovery-delay=10000 --disk-store=DataPersistence --enable-statistics=true --eviction-action=overflow-to-disk --compressor='org.apache.geode.compression.SnappyCompressor' --redundant-copies=1 gfsh> describe region --name=DeserializationErrorPOC Name : DeserializationErrorPOC Data Policy : persistent partition Hosting Members : server1 Name : DeserializationErrorPOC Data Policy : persistent partition Hosting Members : server1 Non-Default Attributes Shared By Hosting Members Type | Name | Value --------- | ------------------ | --------------------------------------------- Region | data-policy | PERSISTENT_PARTITION | size | 3 | cloning-enabled | true | disk-store-name | DataPersistence | statistics-enabled | true | compressor | org.apache.geode.compression.SnappyCompressor Eviction | eviction-action | overflow-to-disk | eviction-algorithm | lru-heap-percentage Partition | redundant-copies | 1 | recovery-delay | 10000 The domain class is deployed on the server: [cid:image001.png@01D6AEBE.BF279570] gfsh>list deployed Member | JAR | JAR Location ------- | ------------------------------ | ----------------------------------------------------------------- server1 | DeserializationErrorDomain.jar | C:\geode\server1\DeserializationErrorDomain.v1.jar gfsh>export data --region=DeserializationErrorPOC --file=geode-storage/DeserializationErrorPOC.gfd --member=server1 Member | Status | Message ------- | ------ | ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- server1 | ERROR | java.io.IOException: org.apache.geode.cache.execute.FunctionException: org.apache.geode.SerializationException: A ClassNotFoundException was thrown while trying to deserialize cached value. Also the application throws a “SpringBasedCacheClientApplication: org.apache.geode.SerializationException: While deserializing query result” exception if I try to execute repository.findAll().forEach((item) -> System.out.println(item.toString())); Claudiu Balcîza From: Anthony Baker <bak...@vmware.com> Sent: Friday, October 30, 2020 09:56 To: user@geode.apache.org Subject: Re: A ClassNotFoundException was thrown while trying to deserialize cached value Thanks so much! The other thing that puzzles me here is that the value is being deserialized at all—I thought we could just stream the serialized form directly into the export file. Anthony