Fail to backup JIRA

[Sagi]

When trying to backup (XML) JIRA, I get the following error:

An exception occurred backing up: java.lang.IllegalStateException: Could not find column 'JQL' in previously parsed query!

The Log Analyzer says  there are two JIRA instances using the same database.

I think the cause of that is I tried to downgrade JIRA and connected it to the existing database.

I already tried all kind of solution I could find, like changing to a new schema (https://confluence.atlassian.com/jirakb/changing-the-schema-for-all-jira-tables-under-a-specific-schema-282173461.html), or running the Integrity checker.

None of those helped.

[Nic Brough -Adaptavist-]

>I think the cause of that is I tried to downgrade JIRA and connected it to the existing database.

There is no way to downgrade Jira, and your attempt to do so has (probably irretrievably) damaged your database.

Your best option is to go back to the backup you took before attempting the downgrade.

[Sagi]

That was too long ago, more than a month...

I can't go back to my backup.

[Nic Brough -Adaptavist-]

I'm afraid there's not a lot we can do with a damaged database like this.  You will probably never be able to repair it, because you cannot know what damage you have done or what data you have lost.

If you've discarded the backups you took before attempting the downgrade, then I'm afraid there is nothing left.  Your only option is probably to create a new empty Jira and patch in whatever data you can recover from the damaged one.