oh yeah I encountered this too. Now I couldn't finished the game...
2 years ago (+1)
I always couldn't get to the end because some walls would disappear like this and I can't interact with other things anymore. I would fall endlessly walking straight through. I've only discovered recently from a gameplay video that there is an ending to this. This is one of the unique and coolest experience to revisit and play once in a while even if I can't reach the end though. 
2 years ago(+1)
woah I commented 165 days ago... there are no new update regarding this right?
I mean just free-falling into white void, and nothing to do after which makes me lost on the game...