“Not enough memory. try again at a different resolution.”

I want to upload this movie to Youtube. But it always says something like "You do not contain enough memory to save this movie. Try again at a different resolution." with a red circle with a white "X" in it whenever I try to save it. I tried literally ever resolution. I even took out some parts and created custom resolutions lower than the regular resolutions. But it still says the same thing every attempt.

What do I do?