Serviio does not see my Samsung TV

For many years I used the terrible Samsung DLNA software. It stopped working suddenly the other day, and upon checking, I found that it no longer saw my PN50B860 TV. Now I'm trying to run Serviio, and it has the same problem. I know the network setup on the TV is good, because its built-in software says it's fine, ip address and all. In Serviio, when I look at status, not only do I not see the TV, there is also no "Add" button. Is there any way to force it to recognize the TV's ip?
Thanks!
Thanks!