I bought ArmA CO on Steam the other day and I went straight into Campaign when it installed. It had started up fine but when it reached the loading screen it began to load, then closed instantly, giving me the message "Warning: preNLOD format in object ca\wheeled\bdrm2.p3d". The first boot camp mission worked, but nothing else. I have yet to try some levels, but by the message, I assume it is the levels with a BDRM-2 tank featured in it.
I'm assuming there is a corrupted file perhaps, so what should I do?