Started up Active Sky 2016 after FSX up to be sure that other programs could add to the menu while FSX running. Added with no problem.
If only it were so simple...
Fact you can add another program to the menu, doesn't mean anything. In FSX, an addon can be written using 3 different versions of the Simconnect runtime: RTM, SP1 and SP2/Acceleration. They are all separate, they can be all installed at the same time (they usually are), and it's even possible, using some magic Windows system (called Side-by-Side), that nobody really understand, up to the point that even Microsoft abandoned in the latest VC++ libraries, to load different versions of them, at the same time, and this is what usually cause issues.
So, if you have the Simconnect from the RTM and SP1 properly installed, but the one from SP2 missing/corrupted, and you have Addon A using RTM, Addon B using SP1 and Addon C using SP2, you'll see that Addon A and B would appear to work normally, while Addon C wouldn't, but that doesn't mean you don't have a problem, without this being an issue of Addon C.
Now, that's just the first complexity level. The 2nd complexity level is that, sometimes, when an Addon uses an older version of the library, the Windows Side-by-Side system might not work correctly for some reason, so the sim would be "stuck" with the RTM version, meaning that both Addon B and C wouldn't work, because FSX is not able to load multiple versions of the libraries itself, which is what the Side-by-Side system is supposed to do, when it works...
Now, that was the 2nd complexity level. The 3rd complexity level, is the different Simconnect libraries have their own dependencies themselves. RTM and SP1 require the MS VC++ 2005 runtime libraries, while SP2 require the "MS VC++ 2005 runtime libraries SP1" (SP1 of the libraries). So, if you have a problem with some of them, the related Simconnect won't work too, and so the addons made for it.
Now,. that was the 3rd complexity level. The 4th complexity level, is that Addon themselves might have DIFFERENT runtime libraries requirements. You might have addons requiring the 2005, 2005 SP1, 2008, 2010, 2013 or 2015 version of the VC++ libraries. This is in addition to the 2005 requirement they inherit from being a Simconnect client application. So, you might have all your Simconnect versions fixed, but still have issues because you have a problem with the VC++ libraries required by the Addon itself.
Just FYI, we require (and automatically install, of course, using the MS official installer) the VC++ 2013 version of the libraries, and the Simconnect version we use is the latest for FSX, which is the SP2/Acceleration version, that requires the VC++ 2005 SP1.
An addon that still use the RTM version, for example, might work itself, and might force the sim into that version only (not normal, but it happens), so you will have some addons working and some not, and the *cause* was the one that are WORKING which caused the mess to begin with so, the usual troubleshooting made in this case, is to exclude all the modules from loading, until you find the offending one. Then, sometimes it's possible to fix the issue, by re-arranging the loading order of the modules in the DLL.XML file, or the EXE.XML file.
Of course, all of this assume the antivirus is not the issue, which is still the most common case of missing menus. The 2nd most common case of missing menus is this one, but unfortunately is WAY more difficult to fix than just disabling the antivirus.
Want to hear ANOTHER opinion ? See this, from Pete Dowson, FSUIPC author:
http://forum.avsim.net/topic/323009-simconnect-gone-mad/?p=1909995#entry1909995I'll quote here the relevant part, where he's saying exactly the SAME thing:
I've got two PCs, one running Win7 and the other XP, and both of them have broken SimConnect installations. I have not been able to find any way to repair either without reinstalling Windows. I actually broke them deliberately (!) in order to research this, but I failed miserably to find a solution other than Windows re-installation (which I'll do one day, if only to tidy up my increasingly rubbish-ridden systems).
In my opinion the side-by-Side library system is the most diabolically convoluted system ever conceived and implemented by Microsoft and when it goes wrong it is fatal.
Of course, you might be saying "but after all of this, how we are going to fix this issue" ?
I'm afraid the best suggestion might not be what you want to hear, which would be switching to Prepar3D, which has FAR less issues with libraries and conflicts. Lockheed Martin suggest all developers should use VC++ 2013 to develop addons, which is what we use, their Simconnect doesn't use Side-by-side anymore, and they don't have the bugged "Trust" sub-system, which is what causes the dreaded "bad addon" message, which appears randomly after you just trust an newly updated module.
Other than that, sometimes you can fix it by removing manually the Simconnect folders from the Windows\WinSxS folder (in Safe Mode) then REPAIR the FSX install from the original install.