@bahaa, you’ll have to give a little bit more information than that if you want a satisfactory answer, which printer are you using, what were you doing just before this message appeared, give some more details leading up to the problem.
The more information and history of your printer we get the better chance we have of helping you ok..
You may look for the WICReset utility, and run from there the status report and read the level of the waste ink container, if that's full. The status report will give you fatal error codes with a short description.