[Osudog]

Looking at your aircraft list

KittyhawkMkIa Kittyhawk MkIa, 1942
KittyhawkMkIII Kittyhawk MkIII, 1943

I dont think these are included in AC Installerv3.5. They were issued with an unofficial buttons file.
Try disabling them and removing the entries in air.ini etc.

You need to be sure that you have no other unofficial aircraft installed.

In my copy of v3.5 the UI version of the buttons file is 838kb not 818kb.
Are you looking in the correct folder?

Yep you got it ash it is the Kittyhawk I have them in a game just for WIP and the like and most new aircraft with the 3.5 will CTD with them in the game so did nothing with them but for the one install thay are in good call