could not remove file

after trying to uncheck a file in the "files" tab, can't do it and get error "could not remove [some file] it's already been removed or it has comments." don't think there were any comments since it was still in draft. i think what triggered it was trying to uncheck multiple things at once (by clicking in quick succession).

leaving that tab and coming back still does not delete the check or allow me to uncheck it. wasn't sure if the file would be included or not until i started the review (it wasn't, as desired).