Welcome to the club! There is a chronic problem with this printer's printhead. HP will send you another one and it will fail soon also. I am on my 2nd one now. Each of them lasted about 6 months.
The REAL problem is an over sensitive method of determining that there is a problem with the printhead. This is why I know this to be true. Both times, I was able to get the printer working again, several times, for a little while by restarting the printer and/or removing and replacing the cartridges. Every time I got it working again it printed PERFECTLY until it cam up with the message again. So therefore, there is either nothing wrong with the print head or whatever is actually wrong with it is so minor it doesn't matter.
SOLUTION: HP should (but probably never will) update the firmware over the internet to prompt us if we want to print anyway. Then if the printer prints fine, everybody's happy. If not, then there really is a problem that needs to be fixed.