Hello,
I have EXACTLY the same issue.
I installed: FSUIPC 3.999w
Purchased & Registered License for FSUIPC3
Installed on Windows 7 Ultimate / 64bit
Fs9 updated to v9.1
If I Launch fs9.1, FSUIP displays my registration information.
Plan-G unable to connect.
FSInn/Copilot/SquawkBox unable to connect.
If I uninstall FSUIP & reinstall without registering, I am able to connect to Vatsim and Plan-G works without problems.
I've have also tried:
1. Uninstalling the Plan-G, FSInn/Copilot/SquawkBox
2. Installing FSUIP & Registering
3. Reinstalling Plan-G, FSInn/Copilot/SquawkBox
This does not fix the issue.
Things only work when FSUIP is unregistered.