I'm going to guess this may have something to do with the dll.xml post that is just above.
No, it doesn't have anything to do with DLL.XML
This error happens because FSX has been wrongly set up to run in one of the XP Compatibility modes, which is not needed, and it also bad for performances, because it start a virtualized environment, and it's not how FSX is configured when it gets installed.
If the Addon Manager is at the bottom of the .xml file list, it will not work, and because it is anti-pirating software, all of your other FSDreamteam or Cloud9 software will act like it is not activated.
It's not dependent by the Addon Manager at all, and it's not dependent by "antipiracy". The issue are other Addons that are listed, that when loaded before, either leave Simconnect in an unclean state or, are compilied with older versions of the Simconnect libraries (before SP2), and don't work well if loaded together with the Addon Manager which is correclty compiled with the Simconnect SP2 libraries. FS Copilot is known to create this problem, but there might be others.
The Addon Manager here is *affected* by what the other modules are doing when loaded before it, the fact that the issue is fixed by moving it at the top, clearly proves that the Addon Manager doesn't do anything wrong, because it doesn't disturb anthing that is loaded after it. You might have had a point if it was the opposite situation: having to put Addon Manager as last, because it might create issues to others if loaded first.