I'm afraid I don't understand which ladder or which boss you're talking about. In the room with Dror Ragzlin? Or Gut? Or somewhere else? If you want to see if any other players have come across a similar issue, then perhaps a screenshot would help.

If you have a savegame you can send it to Larian so they can perhaps diagnose and fix the issue. The "Report a Bug" link on the launcher will take you to the right place on their support site.

"You may call it 'nonsense' if you like, but I've heard nonsense, compared with which that would be as sensible as a dictionary!"