Record layer saveRecord fails with ***java.util.concurrent.ExecutionException: com.apple.foundationdb.record.RecordCoreException: Expected only a single key extension for split record***

I meant getLogInfo from the RecordCoreException itself. It looks like that method doesn’t combine causes, so you’re only seeing the one just created.

Since the problem only occurs when using FDBMetaDataStore, I wonder whether you are storing that in the same (that is, overlapping) keyspace as the records. That happened here, so maybe there could be some explicit check for that.