I owned Telo Air, 3 linxes, and 1 HD2 handset. I had 1 linx in the bedroom, 1 in the den, and 1 in the kitchen (connected to an old Uniden answering machine that connects to 4 Uniden handsets). My HD2 handset was in the family room. This system has worked fine for about 4 or 5 years.
I bought an HD3 and it registered and works fine as a replacement for the HD2. I did not unregister the HD2 or any of the Linxes. So far so good.
Then I decided to use the HD2 in the Den so I tried to register it. Instead I got the message “Max number of devices already registered on the Ooma base unit”. I looked at the Device page and Ooma showed 5 devices - 3 linxes and 2 handsets. So I removed one of the linxes from the wall and unregistered it on the device page. However it remained on the page now without a name - previously it was “Linx2”. It also was without a green or red dot and the option to delete was gone.
Meanwhile, sometime among my troubleshooting attempts (restarting Telo, removing the batteries from the HD2, trying to unregister the Linx) the HD2 disappeared from the device list. It still would not register yielding the same message. So here I am with the device list showing 4 items - 2 active linxes, 1 inactive (unregistered?) linx, and an HD3 handset. And I have an unusable HD2 handset.
Any help appreciated. I would like to use my HD2 handset!