Fly hangs but can do discovery flights

By the way, when you reinstalled the sim, did you clean the Windows registry? The process monitor utility from sys-internals shows that the sim is accessing the registry a lot. In the old days, the registry could be a nightmare and since the sim is (probably?) reusing a lot of old code, maybe something in the registry is corrupt? Just guessing, I have no clue what is happening under the hood. Trying to pull every string I find.