Bug at the cube after completing rotten area

[v]

I cleared the rotten room where you light the rope on fire and the body bag makes a hole in the ground and you jump through it. When I did that the cube puzzle wont let me progress to the next area even though I have closed out of my game multiple times and tried everything I can to let me progress. I know I should've had another save file to be safe, but I don't think its fair this bug is not lettin me continue the rest of the game when I have done everything up until now...anyone else experience this? Anything else I could do?
I don't know if its worth mentioning but when I came back to the cube room there was a glitch where I saw a pile of rocks and a sword sticking out of it for a few seconds and then it went away...

[SallySandbox]

this is ♥♥♥♥♥♥♥♥. gam is now broken, cant progress. i did everything reddit said and i cant progress. im extremely pissed off. basicallythe internet is sayimg to restart from the beginning. such bull. it literally breaks the game. i have adhd i dont wanna have to restart the whole ♥♥♥♥♥♥♥ game

[PlayNice]

Lower your graphics settings, apparently this is a bug with the graphics getting in the way of loading the new area.