Hi, I have an HP Envy 4500 printer that's about 18 months old. It's worked fine until I changed the last black ink cartridge to a new hp one (301 XL), then it kept coming up with the error message 'Incompatible cartridge. The indicated cartridges are not intended for use in this printer' . I ended up buying another cartridge for it - also a genuine hp one - but the error message is still coming up and it won't print. Both times it has printed a few things, then a few days later comes up with the error message and stops printing. I've tried contacting HP but they say they can't help as it's out of warranty. Any advice as to what it could be would be greatly appreciated. I really can't afford to buy another printer so soon. Thanks, Sally