In my case nothing described above has helped. What happened in my case: despite Uniden own answering system was turned Off all the time somehow part of the one of the live phone call/conversation has recorded on Uniden's own answering system. And even Uniden's own answering system was still off there's was one recorded message. I only was able to see it after turning that system on and only after its own greeting message has played I was able to see there is "1" blinking meaning there's one new message. Only after deleting it on Uniden's own answering system the blinking indicator on all handsets has stopped. After that I turned Uniden's own answering system off again.