So I go and delete the Prepar3D_Default.fxml so it rebuilds again and able to start P3D V3... it does fine until I save a flight of my own

 

Then next time I start P3D, it says the file Prepar3D_Default.fxml is corrupted.. I now have to delete this file and restart p3d

 

Hmm

 

Any ideas?

Sorry Manny i cant help you.   I do get a scenery error 9/10 when i shut down the Sim,  everything still works ok though, A couple of people are getting the same error