My community folder is not in the Default Location, so the Installer can not find it...
The installer will surely find the Community folder, even if it's not on the default location. Could you please check the last line of this file ?
%LOCALAPPDATA%\Packages\Microsoft.FlightSimulator_8wekyb3d8bbwe\LocalCache\UserCfg.OPT ( if your MSFS is the MS Store version )
%APPDATA%\Microsoft.FlightSimulator\LocalCache\UserCfg.OPT ( if your MSFS is the Steam version )
The last line should contain a line that says:
InstalledPackagesPath
Then a path, which should match the location of your Community folder. Could you please post this line ?