OK the E90 problem is a ink carrier error, it is usually after changing the ink, first make sure the ink lid is closed properly and clicks in to its lock if not press all the ink down it may nor be seated properly, if that doesnt work lubricat the silver slide at the back of the ink holder (the one it slides back and forth on) with a little silicon grease or BP jelly (petrolum jelly) not much just a little it may be the slide bearing has become tight this will give the same error, also check for small pieces of paper the error is the carrage is not locating properly because it is too tight, or sticking or and obstruction. Cleat it and everything should be OK
Marc Engineer, February 2009