We successfully installed Xibo CMS on a machine running Windows 10 Professional, connected to a LAN.
Testing the local address 192.168.2.129 via a browser works fine. But, at the player side we entering the correct details the player is unable to connect.
As there are only two parameters inserted in the player, address + CMS Key, what could possibly be the problem.
What message do you see on screen when you enter the CMS key and URL into the player settings? if possible, please provide screenshots of any messages or errors.
Is you player connected to the same local network as your CMS? If not this could explain why it is unable to connect.