I have a problem!In MD-11X, I want to connect "External Power", but I cannot.Things happened to me:I arrived at Zurich Airport.(I have flew the Tutorial Flight) Shutted down Engins and all 3 IRS systems. I wanted to Shut down APU, so I needed to connect external power... The problem occured! I pressed the LSK 1L key to make "Power mode" BY REQUEST, and pressed the LSK 1R key. But there were no changes on FMS. I did retry more than 10 times, but the outcomes were the same.So, I reinstalled PMDG MD-11X. And tried again... The same consequence!I found this thing:When I push the LSK 1R key, "AVAL" message appears on overhead pannel, but it disappears in no time.(a frame or two)So I cannot connect external power.MD-11X's version: 1.21and I'm using Flight Simulator X on Windows Vista.Please help me.

Make sure you have granted Full Control on the Flight Simulator X folders. UAC is preventing the connection by restricting the program from overwriting files in the folders.

Thank you very much scandinavian13!I didn't know that I need to have granted Full Control.I tried as you told, and succeeded!

Welcome. Glad it worked.