Plant Connectivity 15.1 error on connection to an OPC UA Server

Hello,

I am trying to connect SAP PCo 15.1 to an OPC UA Server, i click the browse domain button in order to get the available OPC UA server but i am not getting result at all, i wrote the discovery server name and the server endpoint address but the result is the same. I tried to connect another OPC client to  the OPC UA server in order to make sure it was not a network problem and the connection was successful.

Thanks in advance, Victor