We are getting the below error in report server DB.
The version of the report server database is either in a format that is not valid, or it cannot be read. The found version is '164'. The expected version is '163'. (rsInvalidReportServerDatabase) Get Online Help
How we fixed this issue:
1. update ServerUpgradeHistory set ServerVersion=163 where UpgradeID=3
2. select * from ReportServer.dbo.ServerUpgradeHistory with (nolock);
3. Restart the reporting services.