Originally Posted by Ergonpandilus 
@GhanBuriGhan: Somebody was having same kind of issues with 1.72 update. You might want to check worldofgothic forum about it. Just take backups of your savegames. v1.74 should not break the savegames, if they are from version 1.7x.
Turns out it was a simple thing: installing the patch resets the Alternative Balancing to off, and because of that my savegames were not recognized. Turning AB back on fixed it.