Version: Version 4.2.0a4 (446ff42468b3)
Version control plugin: Perforce

1. Two editor instances, both updated with latest files from depot
2. Instance #1: Modify e.g. a material and check it in
3. Instance #2: Modify same material and check it in (without getting latest)

(Can also be repro’ed by e.g. trying to submit file locked by another client)
Result:

Message from P4 shown in console:

Version Control General: Out of date files must be resolved or reverted.
Submit failed -- fix problems above then use 'p4 submit -c 17'.

But then version control gets disabled

At least in this case, version control shouldn’t be disabled, as we would like to resolve files right away.

Workaround is to click “Settings” and reconnect to Perforce.