The PCL XL Error "Illegal Media Source" is possibly due to a driver fault, but is usually caused by selection of a Paper Tray (Media Source) which is not configured on the device (i.e. the driver and device are 'out of step' as regards what trays are available).
You should only get PCL XL errors when you use the PCL6 driver (PCL XL is the 'official' name for PCL6).
Hence, switching to use of the PostScript driver will mean that you won't get this (or any other) PCL XL error (but you may, instead, get PostScript errors of course).