GX4020-Paper tray was changed from Rear Flat Tray because of a conflict with another printer setting

[bluehaze911]

I have a new GX4020.  I put an 8-1/2x11 matte photo paper on the rear flat tray.  I selected that size paper, matte photo paper and high quality.  I click OK to print and get the message "Paper tray was changed from Rear Flat Tray because of a conflict with another printer setting.".  I tried changing the paper to plain paper, paper size to 8x10 & disabling the feature to recognize paper type but I still get that message.  I have no idea what setting is in conflict.  How do I find out what setting is the issue or force the printer to accept the settings I've chosen?

[Hector]

Hello,

If you are printing on Matte photo paper, you can load that paper into the rear tray using the steps in the link Here. The Flat rear feed is for use with thicker paper like paperboard. To check what settings that you might be getting the error with, you can reply to this message with the specific operating system that is on the device that you are printing from and what program you are using. Once we have the information, we can provide some troubleshooting steps or suggestions. For a more immediate resolution, you can contact support over the phone at 1-800-652-2666. Our agents would be happy to check what is causing the problem.

[bluehaze911]

Thanks. I eventually did contact support & they explained that only thick paper can be used on that tray.