I think the exception error says plenty.
“Couldn’t find a place to stop rolling back. Perhaps the script > changed in an incompatible way?”
I don’t know how old your save might be but sometimes - for the sake of fixing bugs and other stuff - the script gets modified. Which ends up breaking some saves.
There’s not really much Arc can do in that regard, since the game is still a work in progress there’s a chance scripts will change. Either due to tweaks or bugs that went under the radar.
Ideally it’s recommended you don’t save in the middle of dialogues.
Also places like the protagonist’s bedroom are “safe spots”, saves there are pretty much guaranteed to keep working, which is why the game autosaves only when you go to sleep.