Hey @Ivan_ya,
We’ve investigated the issue and it’s caused by the ThemeProps migration code not being ran properly when upgrading from Mattermost 3.2 --> 3.4
There are two workarounds that should help resolve the problem:
- Upgrade from 3.2 to 3.3 and then from 3.3 to 3.4
- If you’ve upgraded from 3.2 to 3.4, run the following SQL query to make Mattermost rerun upgrade steps that were not properly completed
UPDATE Systems SET Value = '3.1.0' WHERE Name = 'Version';
Please let us know if the above help resolve the problem.