This my continuing problem. At some point couatl no longer shows on the add on manager menu. Of course then I can't get any buildings at supported airports. Couatl is still on my computer, it just doesn't show on the menu. If I restart my PC and load FSX couatl is back on the add-on menu and everything works. It remains on the menu for a certain amount of time, but at some point it drops off the menu again and I have to restart. I've deleted couatl and installed the latest version several times to no avail. I guess I can live with the restart, but after a restart it takes FSX much longer to load. It would be nice to solve this.