Hi tcigrand,
Thank you for using the forum. Have you installed the latest driver for the Phaser 6510 and the macOS Big Sur? If the latest driver does not help I suggest that you call into our support department for assistance @ 1-800-821-2797 or 1-800-835-6100 for more assistance.
Hello! I recently purchased a new iMac, updated toMac OS Big Sur, and have installed my Phase 6510 but it constantly either stops printing part way through the print job or tells me to check the paper tray. Looked all over for newer drivers but had zero luck Worked like a champ on my old iMac running pre Catalina OS. Any help woild be greatly appreciated!