Message light continually lit

There are different reasons your message light may come on besides voice mail calls. The situation that started the message light needs to be completed before it will go out. I cannot be sure on your particular phone but quite often when I see this problem on other business phone systems it is because someone on another phone in the system tried to intercom and there was no answer setting off the message waiting indicator. (This may require other buttons to be pressed by the caller making it a rare occurrence) If so, you may have to press the message button to return the intercom call. The trick is the other phone needs to be answered as well or the system will not shut off the MSG light. Are there any unusual messages, icons, etc.. on the LCD? If this is not the case, you MAY be able to force the light off by leaving yourself another message and then retrieving the message.