This is because on the 6280 you do have two different toners, those for people with contract (Pageback) and those for people without. It's merely so that you cannot missmatch these two with each other.
There is a chip on the back of the toner which the machine uses to register if it's the correct toner or not.
You can mimic this error by just putting some paper over the chip and then putting it back in the machine.
Could probably be explained easier, but hope this helps!
ok, on further research this error is showing up because i have used non OEM toners. yet why is it doing this error on OEM, and not the others?
i recently installed a new xerox brand black toner, which printed fine, then the next time i woke the printer up it had the c crum error for black toner. restarting printer, reinstalling toner still had the error. so i replaced it with a different toner. now i installed a new cyan one, and after coming out of sleep mode it is doing the same thing....