Render is causing reaper to not respond

Not sure why this is happening. does it if i try to render the whole file or just a portion. boourns. anyone got some helpful advice?

I get this if Reaper can't get at the output file, typically because it's open in another app. It'd be nice if it just told you that but it seems to sit there retrying.

Also happens (I think) if it's trying to render to a non-existent location. This can happen if you move a project from one PC to another. The project will try to render the file to the old desktop or wherever, so be sure to set the render location properly.