[Siwi]

Obvious thing to check, but is the toner level sufficient? Some printer manufacturers program dirty tricks where the printer will refuse to function if the level gets near empty on just one drum.

Following that, I would try a test print on ordinary copy paper. It may be that the thicker stock is causing adhesion issues if it has a smoother surface, which is leaving a residue of unprinted toner on the rollers or else some other kind of interference with the imaging. Either that or it can't grip the paper properly as it goes through the machine and this is causing failed prints. There should be a cleaning cycle you can run too.