File Error: Access Denied when rendering

Final Cut Express, I have 3 video tracks and 2 audio tracks that I have to sit for an hour at a time for it to render and when it gets to 99 or 100 percent, THEN it gives me a "File Error: Access Denied" message, so after 4 times of trying to render the stupid thing (sitting here for an hour at a time) I just chopped all the tracks down to 30 seconds (just an arbitrary number) and rendered it to see if the files themselves were faulty. Nope, they all rendered perfectly fine with no issue whatsoever. So I stretched all the tracks to the original length they were before, and I get the same error message. It's infuriating to have to sit and wait an hour to THEN be told there's an error, and even moreso that it won't tell me what the problem even is. So can anyone help?

It's three video tracks stacked on top of each other (same length) and two audio tracks and I have no clue why I keep getting this error or how to fix it. All tracks (audio and video) are uninterupted clips (no mixing and matching within the individual tracks, they were all one continuous file) can anyone shed light on this issue? And whatever further info you need just ask for exactly the information you need and I'll provide it. thank you!