Problem is solved!

Today I noticed that also Active Sky lost connection to the flight simulator. Therefore I downloaded the newest version of FSUIPC (3.98a) and everything works now perfectly! :)

Thank you anyway for your hints and tips!

Yes, both Plan G and WideFS are running as administrator...

I followed the install instruction but have still the problem that I cannot connect to the FS9. I was able to build the database and both the Flight Simulator and WideFS show the status "connected". But if I click on the "Connect" button in the Home menu I get the error message "Unable to connect to Flight Simulator. (Is FS running?) If you are using FS9, check you have FSUIPC installed. Please see the log for more details.". The logfile says "Error opening FSUIPC: FSUIPC.FSUIPCException: FSUIPC Error #14: FSUIPC_ERR_RUNNING. FSUIPC is not running." But FS is running and so is FSUIPC.

My config:
- Server: Flight Simulator 9 on Windows 7 x64, full version of FSUIPC 3.90, WideFS installed and running
- Client: Windows 7 x32, Plan G 2.05

Status on Fight Simulator window says: "WideServer: 1 connected" and WideClient says "Connected"

Could somebody help me getting Plan G up and running?

Thank you for any help!