This is classic misery. After doing FSDT GSX update along with live update about 4 days ago, my couatl stopped starting up in Prepar3D (latest 4.5 version), I beat my butt into the ground, going through the usual drill, uninstalling, reinstalling, going through NIS Smart Firewall, Insight, AutoProtection, and then checking every possible forum post related to this, and searching for anything under the sun. So, tonight I was at it again, and decided to search for "Where does P3DV4 start couatl", since I really don't know where that instruction is. So, I got to a short post in AVSim that I had partially read before dated 2015. But I decided to read the rest of it and the last reply dated March, 2017 said this: ------Posted March 23, 2017
I was able to solve it using compatibility settings. On my system, couatl.exe must not be run as administrator- that seems to have been checked on install. I always thought everything should be admin level, but I guess win10 is funky like that.--------.
So, I already knew that my couati did have the adminstratior box checked and it was done when GSX installed (I uninstalled all other addons for troubleshooting, since they all need GSX V2 anyway), and I had deleted the addon manager folder many times so that it would get reinstalled fresh. I made the wrong assumption that it was needed. So, the administrator box in the compatibility window was checked but greyed out. I was too burnt to find out what did or didn't have rights, so I checked "Change for all users" so that I could now uncheck it. Guess what? The couatl started great and the addon manager was working correctly in P3DV4! Why oh why isn't this listed as a major configuration to check along with a list of the top things to check for each type of OS and antivirus program? Here is a link to the AVSim topic:
https://www.avsim.com/forums/topic/471095-fsdt-couatl-not-starting-in-p3d/. Hope this helps somebody else with Windows 10.
