Don, I may have found the SOLUTION for this old thread.
I had the same ERROR as James had, but he c(w)ouldn't say what the problem was.
For the last 3 days, after getting interested in AIFP and after reading this topic over and over again, the problem was found...
In the registry there was mention about \STEAM_MSFS\HLM_Packages. Since steam has never been on my PC this was very strange. Mind you that this new PC was setup from an SSD that was in my older PC. So the registry was corrupt. After using CCleaner (found several faults) the mention to steam was gone in the registry.
But that was not all, and maybe NOT the problem.
In c:\Users\Bassy\AppData\Roaming\Microsoft Flight Simulator\*.* there was a UserCfg.opt "different" than the UserCfg.opt in c:\Users\Bassy\AppData\Local\Packages\Microsoft.FlightSimulator_8wekyb3d8bbwe\LocalCache\*.*
The last line in the formal one read: "InstalledPackagesPath "I:\STEAM_MSFS\HLM_Packages"
and the one in Local\Packages was InstalledPackagesPath "I:\MSFS2020"
So after copying the one in Local to the one in Roaming, I can work with your fantastic program like I did for FSX.
Hope this helps other people using AIFP without errors.
Regards
I had the same ERROR as James had, but he c(w)ouldn't say what the problem was.
For the last 3 days, after getting interested in AIFP and after reading this topic over and over again, the problem was found...
In the registry there was mention about \STEAM_MSFS\HLM_Packages. Since steam has never been on my PC this was very strange. Mind you that this new PC was setup from an SSD that was in my older PC. So the registry was corrupt. After using CCleaner (found several faults) the mention to steam was gone in the registry.
But that was not all, and maybe NOT the problem.
In c:\Users\Bassy\AppData\Roaming\Microsoft Flight Simulator\*.* there was a UserCfg.opt "different" than the UserCfg.opt in c:\Users\Bassy\AppData\Local\Packages\Microsoft.FlightSimulator_8wekyb3d8bbwe\LocalCache\*.*
The last line in the formal one read: "InstalledPackagesPath "I:\STEAM_MSFS\HLM_Packages"
and the one in Local\Packages was InstalledPackagesPath "I:\MSFS2020"
So after copying the one in Local to the one in Roaming, I can work with your fantastic program like I did for FSX.
Hope this helps other people using AIFP without errors.
Regards

