Export Audio Mixdown - NOT WORKING! (C5)

Hey guys.

Trying to export a rough mix, and the meter is just stuck at 0% and won’t budge. I’ve just done exactly the same thing with another session recorded at the same time with mostly the same fx/VSTis, and not a problem was encountered. Any thoughts?

I’ve closed and re-opened Cubase and Restarted the PC but to no avail.

C5.5.3,btw. On PC.