At some random point after upgrading from Snow Leopard to Mountain Lion was unable to add new printers.

As I don’t really add new printers on a daily base, I have no idea when it actually happened or what might have caused it.

• If I deleted an existing printer, and tried to readd it, it would throw errors at me.
• Plugging in (known) printers would pop up the dialog "click here to install/download/search for the printer driver", even though it was installed. Clicking install would give me an error no drivers could be found.
• Dymo Labelwriter shizzle stopped working.
• The driver list (system pref > printers > add > select printer software) would be empty, while on another Mac it was fully populated.
• Mac would never find the printer driver for the printer, requiring manual intervention (but, yea, as the list was empty, there wasn't much to select).

This is, as you might guess, quite annoying. Unable to print any new labels or print out any papers (and invoices ! -.-) ) I had to use another Mac just for printing.

Things I tried:

• Thinking it was Dymo driver problem fucking up my ML: reinstall a million different version numbers: didn't help
• Thinking it was Dymo driver problem: remove Dymo from /Library/Printers and reinstall: didn't help
• Manually select the driver when trying to add a printer (Dymo printer in my case, under /Library/Printers/Dymo/bla/something): didn't work
• Reinstall Mac OS X ML without formatting: didn't help
• wipe drive, reinstall and restore all my files/settings: didn't help
• wipe drive, reinstall mac os x ML cleaning and start fresh: 50% of the newly installed apps were crashing (for example: Chrome was unable to start on a _clean_ system), but this is probably an entire different issue. Although I was starting to think my SSD or RAM was fucked.
• wipe drive, reinstall and restore only a part of my files: after trying a few times I found out NOT importing "other files" (which was, the first time I tried, around 20-30Gb... no idea what that was) and "personal settings" (but network settings were just fine): this caused printers to appear in my printer driver list again. Hooray! However:
  • Installing my network printer at home (Xerox) worked, but caused the driver list to go empty again, and printing actually never worked (at this point I was blaming Xerox for having shitty drivers, but I was wrong)
  • (after retrying a wipe-reinstall-half-import:) Installing the Dymo printer worked, but the Dymo software couldn't recognise any printer and this caused my driver list to be empty again
• (by now you can guess how many hours I've spent on this shit while I definitely had more useful things to do).
• Tried manually downloading printers
• and probably a lot of other stuff I would rather forget about

The solution:

After thinking whether I should just buy a new Mac and start fresh (I did actually never wipe my data since, well, probably my Powerbook), and been carrying the same settings and files over my various Macs. But I am just not ready to spend another 2500 euro on a Mac right now.

For, perhaps the first time ever, I went to ~/Library/Printers with Finder… I noticed all my printers were still in that list (even if I hadn’t any printers in system pref). And they are executable packages. They were .app packages actually.

Do note the difference between /Library and ~/Library.

Double clicking any of them resulted in a new yet very useful error message: “print service is not available”.

After a quick Google I came upon this page (which, for some reason is outdated), and that leads to this page (which doesn’t include ML and the Lion explanation I didn’t quite understand). But after some more Googling: tadaaa (#3): Ctrl-click (or right click) in the (probably non existing) list of printers and select “reset printing system”. I have no idea what this does, but suddenly driver names populated my driver list again. Hooray.

Disclaimer: I have yet to add an other printer (I don’t have any printers in my apartment, only at my parents’ house or at the office).

Things I love more and more:

Time Machine!