Just changing the skin line in the MPR replay file wont work, Because all the other code around it is also telling it to use the skin.
So change the skin back to the one it was on, And see if that fixes it.
It is still possible to edit replays without crashing LFS. This is a hacking hazard. aka. Open a modified replay someone sends to you and it could potentially destroy your computer, as it could give the hacker complete access.
Waiting for the devs to post this officially, I emailed them about it 2 days ago and they confirmed it is real.
I think he was asking whether he can use his "serial(crack maybe?)" On the official download from www.lfs.net.
Dario Sudac, Once you download the official LFS S2 from http://www.lfs.net and BUY S2 you will not need a serial, Simply open the game, click unlock and enter your username and GAMEpassword.
This will allow you to play S2.
Translation to Croatian:
P.S. Dont use a crack mate, Or mention that you do, This will most likely get you banned from LFS.