Render / Export Error - Premiere Pro - Error compiling movie?

Hi there,

I'm having trouble exporting and rendering my film. It seems to keep coming up with this error message - always Error code: 5. I'm wondering what the reason for this could be? I have exported this film previously from the same source as I'm trying to now. The only thing that has changed is I've edited the audio track. It was stereo before, and now I've imported a new mono mp3 track in.

Could this be part of the problem?

Please help!

Thanks

Lauren