MSSQL - Database corrupt after restore and upgrade on another instance

Just wondering, if someone got into the same "trouble".

We'we got a mssql 2008 r2 (10.50.2789) server and 2014 (12.0.2000) server and there's a process of backup on 2008 and restore on 2014. Everything was going fine, till today. DB gets correctly (without error/warning) backed up, restored and upgraded. DBCC CHECKDB on source is ok and DBCC CHECKDB just after restore fails on the target.

I would raise a ticket to microsoft, if it wasn't the most confidental db in the house ;)