I was easily able to jump through the closed door, which doesn't open, into a house in the town Vybor. Here are a few screenshots that I got, since pictures tell a thousand words.
- Legacy ID
As you can see, in the photos I actually am inside of the house, which was not supposed to be entered. I did this by running up to the door and jumping through it.
Getting back out was easy; All I had to do was jump back out via the same way I got in. That was the only way to get out, as the house had invisible walls enclosing me everywhere but where the un-movable door is. This is not a serious issue, and I'm sorry if it's already been reported.