Okay so I hope that I am able to have this make sense because this is extremely confusing to explain. So a few weeks ago I downloaded Imaginesims Atlanta scenery for FSX and I had a TON of trouble trying to install it and after awhile I gave it up as a lost cause. So then a couple of days ago I decided that I would try and install it again. So I read through the manuals and scoured the internet and I finally figured out what I had done wrong. After successfully installing it I went up to my FSX tool bar and clicked on "Add-ons" and I found to my horror that everything was gone off of that tab, Couatl, GSX, Addon Manager, Ultimate Traffic 2, etc. The only thing that remained was something called "FSUIPC." I wondered if this would affect my game and it sure did, a lot. So I went to one of my installed sceneries and found out that all the buildings were missing, and the same thing for all the addon airports that used Couatl. It has happened to me before so I was thinking that I'd be able to fix the problem. So I also checked to see if my addon planes were also fine. I loaded up my Quality wings 757 only to find out that all the panels are missing, and outside the airplane some of the landing gears were missing and the flaps were down with the spoilers up. I loaded up my PMDG 737 and the same thing happened (except that there was nothing wrong with the outside of the plane). I am really at a loss here, I have no idea what to do and I don't want to mess with anything to mess it up further. Any help is appreciated! If you need me to elaborate on anything don't hesitate to ask. Thank you! 

I guess I would start with reinstalling the addon manager from FSDT.

https://www.fsdreamteam.com/products_addonmanager.html

and see what the situation is after that.

Maybe you could also make regular backups which you could use to reinstall a previously working version of the sim

 

b rdgs / Dick

2 hours ago, alexandermartin said:

 So a few weeks ago I downloaded Imaginesims Atlanta scenery for FSX and I had a TON of trouble trying to install it and after awhile I gave it up as a lost cause. 

I am am curious as to what the issue was? After you download the installer you just click on the installer and run it. The install is automated and shouldn’t take any work on your part.

 

 

2 hours ago, alexandermartin said:

 So then a couple of days ago I decided that I would try and install it again. So I read through the manuals and scoured the internet and I finally figured out what I had done wrong. 

How did you read through the manuals if it didn’t install the first time? 

So what had you done wrong and how did you get it installed?

Providing these answers might give a clue as to how your FSX got messed up.

You can do as Dick said and either reinstall Addon manager or download one of the FSDT sceneries you own and reinstall it. This should get the FSDT stuff working and also your QW airplane. 

As to you Ultimate Traffic l, it’s sound like it got turned off in either your exe.xml or dll.xml dile, or was deleted completely.

However, I not knowing how you installed the Imaginsim scenery, their installer shouldn’t do anything to those other items.

I’d be interested to know what you found by “scouring the internet” and reading the manuals to see what you did to get the installer to work. Sounds like a lot more than was necessary.

It sounds as though the dll.xml file was corrupted during the installation. It needs to be checked and, perhaps, reconstructed. You might post the content of the file here.

DJ

Most likely the dll.xml as stated above.
If you post the code, use the "<>" code function in the forum posting menu. That way it won't get pooched by the forum parser.   
Also, post the whole code from top to bottom, little chunks will do absolutely no good.