HELLO, I can not print on the back cover. The option is disabled. Anyone know the reason, please?
You would need to call Xerox and spar it, it is definitely broken, that said, it is broken on a great many devices, always FujiXerox.
But FujiXerox isn't the issue here, Xerox is.
Take your D125 as the example, if you get the driver from Xerox, it is exactly as you see in yours, and has been in drivers going back to at least 2012.
But get the driver from FujiXerox.com, and the option works perfectly, as seen here.
So it is definitely Xerox that has a broken driver.