I have never seen "E-99" but I have seen "Eject," which has typically meant that the connection between the head unit and Keg is lost. It has happened to me most often when I have taken out the DMS and put it back. Sometimes, the DMS does not seat properly, so make sure it is pushed in all the way. It is occasionally necessary to disconnect the cable from the Keg and reconnect to get the head unit to recognize it again. Lastly, you may have to reset the head unit. Not sure which head unit you have, but there is usually a depressed reset button somewhere on the face of Kenwoods. I hope this helps.