There is definitely some internal problem with your printer. May I know which model you have? How old it is? I won't recommend doing anything major if you are not experienced. I would suggest you take it to the respected service centre. You can try cleaning the heads and The tank with a plain cloth. Reseat the cartridges if you can then try these steps/ (these problems occur mostly in Epson printers, so I am guessing you have a triangle shaped button, right?)
So - Press and hold the triangle button and the color button, now switch off the printer while still holding down the buttons. Keep holding until the lights stop flashing. Next, press down the color button only , then while holding the color button press off, keep holding the color button, until it turns back on and then release.
This is the waste pad error message and these steps should eliminate the error, atleast I hope so, best of luck!