Error with Fetch Smushed Images

Hey,
When I hit "fetch smushed images" I get an Error with file 2859, which I have no idea what that means since there are no files with that name. I tried submitting a support ticket within the dashboard as well and it wouldn't send, really frustrating.

So yes it seems as if if stuck because of this error and can't finish optimizing my images. Not sure where to go at this point.

Would appreciate your quick feedback on how to resolve this issue.