I don't know why all the PMDG aircrafts experienced very strange tracking "error". For the entire flight the aircraft was heading across it's track by about 15 degrees. The magenta line on the ND was pointing off to the right by 15 degrees while the aircraft's track and heading were normal. The aircraft however was tracking the magenta line.All the pmdg products have the same issue. I've tried with winds and without winds. All got the same. The Navdata is updated to cycle 1008 and FSX is updated to Acceleration.Pls. help.Sagan Lo

I don't know why all the PMDG aircrafts experienced very strange tracking "error". For the entire flight the aircraft was heading across it's track by about 15 degrees. The magenta line on the ND was pointing off to the right by 15 degrees while the aircraft's track and heading were normal. The aircraft however was tracking the magenta line.All the pmdg products have the same issue. I've tried with winds and without winds. All got the same. The Navdata is updated to cycle 1008 and FSX is updated to Acceleration.Pls. help.Sagan Lo

This is usually due to an error in your windows registry, easily fixed by using the free registry repair tool from Flight1. Run as admin if you are using Vista/W7. Hope it helps.

Do two things:1. Run the Flight 1 Registry repair tool (run as admin on Vista/7), select the FSX option and point it to the location of your FSX.exe file.2. Browse to your C:\Program Data\Microsoft\FSX folder (it's hidden by default, turn on show hidden files and folders in the Windows view options) and delete the Facilities and SceneryIndexes folders. FSX will rebuild them on the next launch.That should clear up the issue and allow the plane to read the sim's magnetic variation information again.

Thx all. Can I ask the names of the Facilities and Scenery Indexes folders in the FSX folder? I can't find them after following your instruction.Thx.Sagan

They're not in the FSX folder, read what I wrote carefully, it's the hidden PROGRAM DATA folder you need, not the Program Files folder.