In the ROC you would get the following error while trying to modify the details of an artifact with an artifact type of "Repository": Unexpected error on server [null]. Please refer to server logs with timestamp [2017-12-22 10:44:26].
When reviewing the nolio_dm_all.log file for the timestamp mentioned in the UI error it shows: Artifact Controller Method Error
CA Release Automation 188.8.131.5211
CA Release Automation 184.108.40.20607
This has been fixed in the a cumulative patch released for 6.4. Build 220.127.116.1135.
This has been fixed in the a cumulative patch released for 6.5. Build 18.104.22.16835.