It's really disheartening yeah. Me and my brother stopped playing because of this bug. We can't progress further to the Nameless Isle which we were hoping we could do at least. But that requires the game to "clean up session" that ultimately causes the crash.
This happened to our save while we were organizing our inventory at the Lady Vengeance and buying stuff from Driftwood square. It was too late though when we figured it out and a lot of progress would be lost.
I started again on my own and have been able to manage to get all the way to the Nameless Isle without this happening, so it's not a guarantee that the save gets corrupted with us having this issue.
My inventory is alot smaller in the save which this doesn't happen, so the idea of a glitched item causing this can make sense.
I did a test though and sold every item which allowed me to a vendor and killed him destroying most items in the progress and that didn't solve anything. In that particular save I have items that seem to be stuck in wares and im unable to unmark them for some reason. Like that compass necklace for example.
I just hope that Larian is aware of this and don't have any clue what's going on or in worst case they can fix this from happening again but the save files are beyond redemption.
Either way, im just hoping for the best. Would be nice to see any response from Larian regarding this issue be it good or bad news.