Message saying color cartridge is not compatable, used the same cartridge last 6 months, it is the right one?

if its the same cartridge of course its the right one. maybe its empty? maybe the metal contacts have ink on them? maybe you should turn everything off and turn it back on? maybe you should open whatever software that came with your printer and begin the long and boring process of figuring out why your printer is acting stupid. .... try the easy ways first.|||reboot your printer and computer|||Take it back out, make sure you peeled off plastic and reinstall and make sure it seats all the way in. other than that you might need to take it and have it looked at.