I suspect that the warning was in response to the protection counter (aka waste ink counter).
The ink you lose in cleaning cycles and priming new cartridges has to go somewhere, and your Epson printer keeps track of roughly how much ink it has dumped into some large absorbent pads in the base of the printer. The counter is suggesting that the pads
may be full and further use could cause damage or affect printing. Presumably at some time it will just refuse to print, unless the problem is addressed.
Technically, this condition requires an Epson service engineer to resolve. It is however, possible that you could fix it yourself by resetting the printer and clearing the counter of how much ink has gone to those pads.
Not necessarily the correct method to choose, but you could risk resetting the counter via software...
http://www.ssclg.com/epsone.shtml