Universal Media Server | Forum

Those messages means that UMS is trying to announce its presence on the local network, but isn't allowed to do so by macOS.You should disregard the "Address already in use" part, that's an assumption based on the fact that UMS isn't allowed to bind to the socket. Normally, this can only be caused by the socket already being in use. It seems though that aPple in their infinite wisdom has made some new "security" feature that prevents access to network sockets. Unless you find a way to turn off this "security feature", UMS simply won't work, as it needs to use the network.

I suspect that their "long term goal" is to prevent any software that's not in their "app store" from being run. Since you have to pay aPple on a yearly basis to include your software in their "app store", this is a great way for them to capitalize not only on the OS and hardware, but on every piece of software you wish to run as well. This will however mean that there will be no free stuff unless it's full of ads or it collects your data and sells it. I doubt there are many people that want to PAY aPple to be allowed to give away their software for free.

I understood your first post as if you had already excluded the possibility that the socket was in use. The next explanation then would be some kind of OS level permission to bind that was rejected. I'm glad you enjoyed my theory, but I think you'll see that this IS their long-time goal even if this was unrelated. I also believe that MS has the same goal with Windows and their "marketplace" in Windows 10.

If eyeconnect locks port 1900 its developers are make some serious mistakes though. Port 1900 is supposed to be bound for multicast (it is a "special" port in that it's reserved as the "UPnP port"), which aren't exclusive. Unicast binds are exclusive, but with multicast any number of processes can listen to the same port. As such, the idea that some other software was blocking UMS from accessing it was even more unlikely from my POV.