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Is there any known issues with restoring backups from one MySQL-version to another?

I took a backup on a 5.6 and tried to restore it on a 5.7 and Joomla seems to be working fine but the major component (CiviCRM) did not, mostly rendering "Unknown DB error".

I'm asking to make sure the problem is elsewhere. I could find nothing in the Compatibility section in the docs about this.

There could be problems restoring a newer version of MySQL to an older version, but there shouldn't be any problem restoring to a newer version. The issue would be the compatibility of MySQL itself. Older versions didn't have multibyte support, for example.

CiviCRM can be a real pain because of the referential integrity between the tables. You need to make sure that foreign key checks is off while restoring. Even if you don't, you should get all sorts of fatal errors during the restore. Make sure the tables are InnoDB, not MyISAM and that your new database supports InnoDB. Neither Joomla! or CiviCRM runs without InnoDB.

I have had no problems with restoring a CiviCRM site on a different server before I upgraded MySQL to 5.7.
After downgrading MySQL to the same "series", i.e 5.6, I could restore without problems again.

I will stay on 5.6 for a while, since I was actually hunting down a different problem, and was sidetracked my this problem. Maybe I'll investigate further at some later time.