Cannot login after restoring from backup to v.1.112.4

[davejgreen]

Last week, our GitLab app updated from v1.112.4 to v1.113.0 (or tried to) and we could no longer access GitLab. We would get a 500 error when trying to log in (with Cloudron single sign on as usual). I have been trying without any success since then to get our GitLab back.

Problems restoring from backup
Ideally, we'd just like to restore from a backup we took just before the update. I have tried this numerous times, and sometimes it appears to be running, but we still cannot log in. We just get the 500 error, and the logs show a lot of 500 and 502 errors. I've also seen log lines such as: NoMethodError (undefined method 'id' for nil): and RuntimeError (CI job token signing key is not set):, but I'm not sure what this means. I've tried working with ChatGPT to fix these, but I don't think ChapGPT really knows either.

New Cloudron instance with old GitLab version
We even tried getting a new VPS and installing a fresh, empty instance of Cloudron (v9.1.2 and then v9.1.3). I was sometimes able to install GitLab v1.112.4 and get that running. I then tried importing our backup, but we'd end up with the same 500 error when trying to log in. I'm not sure if this should work anyway though, as it is on a different domain name, so may not be compatible with the backup from the existing domain.

Can't work out the "fix"
I've looked at the information here: https://forum.cloudron.io/topic/15158/postgres-sql-error-update-from-v1.112.4-to-v1.113.0, which is about the same GitLab update, including the links to the GitLab issues. We have a similar log line => Healthcheck error: Error: connect ECONNREFUSED 172.18.x.x:80 that we are getting a lot, but I don't think I've seen the logs lines about PG::CheckViolation: ERROR: check constraint "check_17a3a18e31" of relation "user_agent_details" is violated by some row" in our case. I have tried following the "fixes", but I'm not really sure what I'm trying to do, and our case does not seem to match the information given. In the Postgresql we already have an "organization_id" column, but our "user_agent_details" table is empty. In ~/gitlab/db/migrate# the latest file is 20260212153542_add_work_item_custom_types_namespace_fk.rb which looks like it is from 2 or 3 weeks earlier than this problem. Should there be one from the evening of the 2nd March when our GitLab updated?

Please help!
Any help that gets us back into our GitLab would be greatly appreciated. (Then we might see if we can migrate our existing repo and issues away from GitLab into Forgejo!)