Error going to Act 3 SP

In Single Player, every time I try to go to Act 3 from Act 2 in Nightmare on my Sorceress I get this



I haven't gotten it anywhere else so far, and I have tried multiple times but this response from Diablo 2 is absolute. If I could get some help on this that would be great, thanks.|||most likely a corrupt mpq file

try copying the large mpq files from your cd's to your d2 install folder


Code:

d2speech.mpq
D2XVIDEO.MPQ
d2xtalk.mpq
D2XMUSIC.MPQ
d2sfx.mpq
d2video.mpq
d2music.mpq
d2data.mpq
d2char.mpq
d2exp.mpq

|||or reinstall |||Are you using the -ns command to turn off the sound? That will cause this to happen, as the game tries to play the cinematics and realizes it can't, so goes offroad into a tree. (technical explanation)|||Thank you very much for the answers/suggestions! Noodle takes the prize though xD