A Quit to Desktop (it's not a crash), that fixes when you disable the Addon Manager, it's usually caused by a mix-match between version, as if you were trying to use a .DLL newer then the related set of .DAT files, or vice-versa.
It should be fixed by installing the Stand-Alone Addon Manager, and don't touch any files afterwards.
Note, a mix-match might be also created by the antivirus: if the .dll is blocked from installing, the .DAT (which are not scanned, since they are not executables) will be installed, but the .dll will not, so you might be stuck with an older version of the .DLL, that doesn't match the newer .DAT files.
So, as suggested in several other threads, if you suspect the problem might have been caused by the antivirus, you should install it this way:
- Turn the Antivirus OFF.
- Install the Stand-Alone Addon Manager, don't launch FSX yet.
- Configure your antivirus to exclude the following file from scanning:
\YourFSXFolder\bglmanx.dll
- Turn the antivirus back ON, launch FSX
Another reason of the quit on start, might be a failed and/or corrupted Esellerateengine.dll file, as if you were trying to use an old version of the .dll OR, an older version of the Esellerateengine.dll that has been installed by another product in the wrong folder ( C:\Windows on Vista, for example ), that prevents to be updated by our installer.
To verify this is not the case, check if you have the Esellerateengine.dll file in all the following locations:
C:\Windows
C:\ProgramData\Esellerate (This is hidden by default, you need to enable hidden folders View in Explorer to see it)
\YourFSXFolder
If you have the Esellerateengine.dll in any of these folders, REMOVE ALL COPIES.
Then, install the Stand-Alone Addon Manager, which will restore the correct version in the correct location, which is C:\ProgramData\Esellerate on Vista or Windows 7, or C:\Windows under XP.