Okay... So I installed GSX after reformatting my system, and guess what... SAME SHIT HAPPENING. Don't get me wrong... I realize none of your software cause my problem, they just help me understand that they are there.
I just want to know how to fix this...
As I told you, it didn't fix the problem!
Edit: I did install FSX on the same drive as before (as that drive has never been the OS one, I obviously didn't format that hard drive, should I try to install FSX on the reformatted OS drive?
Edit 2: The problem I get now isn't completely identical to the one I had before reformatting my computer. Before, not even the Add-On menu showed up, now it does. But I still get the error at each start of FSX saying "Cannot init SimConnect error"
Edit 3: And before couatl.exe itself gave me an error, which it doesn't do any more. So that is good. I think it's only the startup error I get, but I think I'll just have to ignore that.
Edit 4: However, the couatl-thingy does not appear under the addons menu.