There's no bug
Just tested it and the scene went through no problem
Did you use the cheat, did you maximise anybody's points or did you change any variables.
Sadly it is a bug. After your comment "did you maximise anybody's points?" i start a new play through, New as in
1)download the game again
2) delete everything old including user data on c / localLow folder
3) follow the walkthrough exactly to the letter
but when i go to emma's home and click the button Knock on door. Game goes into not responding mode...