We recently installed Confluence 6.14.1 using SQL server 2008 R2. There were no troubles reported and everything appeared to be working fine. There is now a lot of data entered into the system.
I recently installed the upgrade to 6.15.1 and it appeared at first to be working fine, but then we noticed issues with an SQL error about an invalid datatype in the logs and various functions were not working. In troubleshooting I noticed that SQL 2008 R2 has not been supported for some time. Since the previous version was working, we want to revert to that version to have it working while we plan for an SQL upgrade.
I have renamed the new folders and restored the zip file backups. It appears that the SQL database was never upgraded (as per the logs I mentioned above it says the schema could not be updated). I cannot find any instructions about how to revert a failed upgrade. Please advise.