I tried to push a fix for the Serena bug. Don't know if that will work because when people gave me their save having the same problem I didn't have the problem at all.
Try redownloading and see if it worked.
I tried redownloading sever times, still got black screens on some scenes, but I did managed to get out of the soft lock by just "letting the animations play" behind the black screen by spaming/holding the enter key, and once I think I'm back in control (which still stays black screened, but I can hear my character move), I just loaded the auto save and loaded after the the blackscreen bug and I continued playing.