Can't Start the Game Anymore

So.. I only played this game.. like... 3 times and it worked 100% fine.

Now when I click start I get this message from Xtrap

"File is changed: W[2007] L[0]

rez\RF017.REZ"

Someone help plz .-.

Don't understand how a file would get corrupted if it worked fine like 20 minuets ago.