Media tray empty! meta-error (?)

[WJG]

My CUPS config was working fine, until I accidentally erased the /var/spool/cups/tmp dir, while trying to solve an unrelated problem. Then I began getting the "Media tray empty!" error message in the web interface, and it showed up in the error log (with debug2). As soon as I replaced tmp, everything began working fine again. I'm certainly no expert at CUPS, but it seems from googling that this might be a "catch-all" error, where a variety of things gone wrong will be interpreted as a media error.

So, if you're getting this error, you might want to broaden your search space (permissions, paths, correct [config] files, installed utilities, etc.). Also, make sure you set logging to debug2 (then restart cupsd). Hope this helps someone.

--WJ