I recently set up my new GX4020 Tank printer and tried to load and print cardstock using the flat bed feeder. First, I got a message that the paper was not loaded, so I selected print anyway. Then I receive an error message to check the transport cover that it may have been removed. That is not the case, it is securely inserted. Both the main cassette and rear paper trays work OK with no error messages. Could it be that my cardstock is too thin? It will feed through and print ok using the rear paper tray.
