Something weird was happening to my system too (it kept asking me to activate and will give error even though the products were active in registry and what not).  I ran P3D in admin and everything worked. 

 

Can you run Prepar3d in Admin mode and see what happens.

Edited June 12, 20187 yr by Skywolf

15 hours ago, Clutch Cargo said:

So after all the bashing of couatl it wasn't couatl after all.

That's the most usual conclusion of all threads related to it, if one is really interested to follow it to the very thread.

It would be helpful to know what the Microsoft support did to help the OP. I checked, and I DO have KB4100403 installed so, I don't think there were any incompatibility with it, maybe something went wrong when installing that update.

I checked the list of files contained in the update, and there are in fact updated versions of the VC++ 2015 runtime, which is what Couatl use.

New versions of the same VC++ runtime are normally backward compatible and applications using it are not supposed to be recompiled but, of course, a failed installation of them would cause issues with every application that use that runtime, but this might not be immediately obvious, because not all apps might call the same calls . and there are many hundreds of them in the VC++ runtime.

Yeah, most of the time addons aren't causing the problem. It's usually the user, other addons, or the operating system.

Well, yay the update installed again 😕

I guess i'll have to revert to another build again.

On 6/13/2018 at 12:30 AM, virtuali said:

It would be helpful to know what the Microsoft support did to help the OP.

The Microsoft support said to revert to another build.