I've the same bug, i'm in the Raedric quest and cannot get out.
I play on Steam and don't know where to find the "save game file" mentioned in :
1. Open save game file with WinRar
2. Delete AR_0707_Raedrics_Hold_Ext.lvl
3. Exit the hold (I went via the Courtyard exit)
4. Rejoice to be finally outside!
Did you know if this bug will be fixed soon ?