Seems like all the forums are full of threads about couatl errors.
On the forum here, the error reports have basically ended, and the only remaining ones, are repeated posts about the same error, which happens because GSX has been disabled, but since people don't search for threads, we have dozen of copies of the same error report. This has already been fixed in our upcoming version, of course, but a temporary solution (re-enable GSX) was explained long ago, and repeated in all threads.
There are sounds reasons outside our control that prevents us to publish an update right now, which will be cleared in the next weeks, and this has also prevented us to release small fixes for such annoying things.
Now it gets almost laughable. So I load up at EGLL and in the PMDG747. Now GSX is showing me a tiny little pushback truck and belt loaders for this plane. And no, I don't have any custom aircraft config's, just the default GSX stuff
The equipment chosen by GSX depends both on the aircraft configuration, but also on the parking size, because some vehicles has parking size constraints too, in order not to show unappropriately big vehicles in small parkings suitable for smaller planes only. However, it has been like this since GSX has been released, nothing has changed in the latest updates.
What might have changed, instead, is the scenery you used, or the AFCAD in use or, perhaps, a PROBLEM with some of your files.
So I decided to go to the couatl menu and rebuild the airport cache. Guess what happened? It not only did not rebuild, all the couatl and GSX stuff disappeared from the menu....***poof*** gone!
That seems to indicate a problem with some of your sceneries. If Couatl crashes while regenerating the cache, it's possible that some of your .BGL has been corrupted. The way to find this, is to enable Logging (if it's not enabled already), then Restart with a Cache rebuild, and exit the sim as soon it disappears.
Then, go to the folder that contains the Couatl.LOG ( usually %APPDATA%\Virtuali ) and see if there's something unusual reported there, like a corrupted file, missing file, a file with 0 size, a permission problem caused by an antivirus that has blocked access to that file, etc.