We just upgraded form YouTrack 5.2 to 6 and noticed that all previous issues have lost their description and comments.
The upgrades was smooth, no error occurred. The database was backed up mutes before the actual restore. The entire system was restored properly, we see the projects, sprints, and the scheduled issues for these sprints,etc.
Our integration with Mail and TeamCity is fully functional as well.
We did another restore of the database as specified by the docs : http://confluence.jetbrains.com/display/YTD6/Restoring+Database+from+a+Backup
However that did not help.
Can somebody give us an advice to what could have happened?