Created attachment 11285 [details]
slightly redacted log of the error and drs showrepl status.
In trying to migrate a Windows 2003 level domain to entirely samba, and preparing an openchange/sogo server to replace a non-exchange mail system, I noticed that drs replication was having issues. Finally, I gave up on getting a Debian system with a 'latest stable upstream' release of Samba and installed an Arch Linux virtual system to test with.
Replicating the behavior I've seen in Samba 4.1.17 with Debian, when the Samba 4.2.3 active directory domain controller attemps drs replication is has the following errors (see the slightly redacted attachment)
How can I collect more data so that this issue might be further isolated and resolved?
Replication with custom schema is now much better in Samba 4.5.0rc1, so I'm going to mark this is as resolved.
Please re-test and retry with that version on the server.