It used to be fairly simple to connect these on the same PC. In Sky Demon it was Go Flying - Connect X-Plane.
In pre-10.45 X-Plane there was an option in Settings to output data to a PC.
Not any more.

Something has happened between the new versions of both programs so that I cannot make the connection any more.

I'd be grateful for advice on how to fix this.
 
Thanks! 

You are welcome. I have been doing network administration for nearly 25 years, so that should be useful for something

Bernd