Can’t render

I have been trying for 3 days to render a video I made. Since the video is 18 minutes but long the rendering takes awhile. I plug in and turn off auto lock and let it render. After 6 attempts it just says Adobe can’t render project. It happens at random times during the process. I really don’t want to redo this video as it took awhile. What could be causing it to not render. I tried rendering another project and it worked fine.