First think I thought was firewall
Same here. A simple check, ideally without connection to the internet, would be to disable your firewall temporarily and see if you can then connect successfully - which would indicate whether it was a firewall issue very quickly. Don't forget to re-enable your firewall afterwards, thaough!
If the firewall turns out to be the issue, then it may take some detective work to see exactly what needs to be done to fix the problem, but may be as simple as:
Settings -> Update & Security -> Windows Security - Open Windows Security -> Firewall & network protection -> Allow an app through the firewall.
Click on the "Change Settings" button (otherwise the list of apps below is read-only)
In here look for the theatre control app, tick the box to the left, and tick the "Private" network box on the right.
Let us know how you get on...
