printer tells me the ink used doesnt fit the printer
Most likely the cartridge is not being read correctly by the printer. First, unplug the power cable from the printer while the power is ON. Wait a couple of minutes. Remove the toner cartridge and close the door. Plug the power cable back in and let the printer power up. Wait until it says to load the toner, then go ahead and put the cartridge in as usual and see what happens. If it still fails, try another toner cartridge.