Movie Render Queue ouputs nothing

I’d been using Movie Render Queue to output ProRes 422 files without a problem until, suddenly, MRQ stopped producing anything. I start the render, the preview window appears and everything seems to go normally. It gets to the end of the render. I go to the folder to retrieve my file – and there’s nothing in the folder! I’ve tried everything I can think of. Any ideas gratefully received. Thanks!