Solution to Microsoft Flight Simulator X “side-by-side” Error

This is a mini-guide for those struggling with trying to get Microsoft Flight Simulator X (FSX) Deluxe, and the Acceleration Expansion pack working on Windows 7 x64. The two big issues which I will cover are the “side-by-side” configuration error message, and frequent crashing while in the game.

side-by-side configuration error

This error message typically manifests itself and reads along the lines of: “The application has failed to start because its side-by-side configuration is incorrect. Please see the application event log for more detail.”

The application event log might look something similar to the following.

Flight Simulator is looking for an x86 Vicual C++ redistributable library. Download and install: vcredist_x86.exe. Once you have this needed library installed, the side-by-side error for FSX and the Acceleration Expansion Pack should disappear.

The above solution was found by lvl99hp on

Frequent crashes in game

Once you’ve finally made it into the game and start flying around, you might notice frequent crashes, particularly after doing anything with the menu. The errors that appear in the event log might look similar to the following and list uiautomationcore.dll as the culprit.

Apparently, using the Visa version of uiautomationcore.dll will do the trick.

  1. Download version 6.0.5840.16386 of uiautomationcore.dll
  2. Place this file in the Flight Simulator X application folder. For example, if you’re running Windows 7 x64, this folder would be something like C:\Program Files (x86)\Microsoft Games\Flight Simulator X.

The above solution was found by Bill_KA350 on

Final Remarks

These two tricks got me up and running and back in flight simulation heaven. It took several hours for me to track down this information, and the correct solutions are not easily found by Google. My hope is that this blog post brings them to the surface for others.

This article is officially complete at this point. What follows is a personal rant on the universal truth that ALL products made, or touched, by Microsoft become pure rubbish. Feel free to move along to more productive things if you wish [such as getting some flying time in].


I spent several hours tracking down solutions to these problems. Every minute of which further reinforces my poor opinion of Microsoft products. I admit that their concepts aren’t always bad, but their implementations have historically been proven to be plain awful.

Let’s start with the side-by-side error message: “. . . this application failed to start because side-by-side configuration is incorrect.” !@#$!@##% what does this message even mean? It adds absolutely no value towards resolving the problem. Searching Google for help yields very little useful information. No, finally after extensive digging, information comes to the surface from the Microsoft developer Web site. Well, what is the user supposed to do with developer information I have to ask? It’s so vague that it doesn’t even help me [a developer] resolve the problem.

All I know now is that the application is expecting some kind of library on the system, but can’t find it. Absolutely no mention about how to find it. Theoretically there’s a command line logging tool that can assist you here: sxstrace.exe, but there is little information on how to use it. The help documentation is (un)surprisingly unhelpful. After even more digging, I found the link I attributed above for this problem with a solution that worked.

I won’t even get into the crashing problem in detail. I swear that every time I use Windows I spend more time trying to just get things to work than getting actual work [or play] done. Even on a clean slate, there are errors and problems left and right that have to be fixed. If I want to sit around and do that, then I might as well use GNU/Linux! At least, in the case of a GNU/Linux distribution it’s not fixing undecipherable problems so much as simply wasting time endlessly tweaking.

It reminds me of my Zune incident. Back when the Zune was the new device on the block, and before I was sucked into the Apple iWorld, I had purchased a nice new Zune. However, the Zune refused to sync or be recognized by my computer. I called Zune support for assistance and spent many hours on the phone to no avail. I finally completely wiped my hard drive and performed a fresh clean installation of Windows XP, and again tried loading the Zune software. Nope. Nothing. Fresh out of the box on both counts and the damn stuff doesn’t even work. I exchanged the Zune for a replacement to see if that was the problem. It wasn’t. I even borrowed a friends old computer and used one of my spare hard drives and performed a fresh clean installation of Windows on it, just to make sure it wasn’t something fishy with my computer. Still, no love making between Windows and the Zune.

That was one of the incidents [among several others] that soured my view of Microsoft to the point of nausea. There is no excuse for this nonsense. I got my money back from the Zune purchase, but Microsoft should have paid me for the time wasted trying to get their advertised product working on unmodified systems.

Sigh — I guess what I mean to say is that I’m disappointed and tired of dealing with Microsoft related manure. And yet, I love the Flight Simulator experience and am stuck in a love/hate relationship between the concept and the implementation. Fin. Enough tilting at windmills for the time being. You gain extra karma if you’re still reading this.

31 comments… add one
  • Ryan Jul 23, 2017 Link Reply

    Thanks the post -fixed my problem straight away thanks to you. Appreciate it!

  • Ranjan Alva Jun 6, 2016 Link Reply

    Didn’t work for me. then i deleted some registry keys having values “VC80.MFC 1fc8b3b9a1e18e3b” in registry editor. after that installed Visual C++ 2005 Redistributable Package (x86) again. It worked.

  • Dakota Dec 24, 2015 Link Reply

    Thank you very much! I know this is an oldie, but it was still useful to me in 2015!

  • Tom Oct 11, 2015 Link Reply

    Didn’t work for me. I installed the uiautomationcore.dll into my main FSX folder. That went fine. I clicked on the vcredist_x86.exe link and clicked run. It ran. I tried running FSX and I still get the side by side error flag every time I try. The vcredist_x86.exe program didn’t let me save it or open it once saved, it just ran. I have no idea what it ran or provided to my computer or where it sent it’s contents or if it had any contents or if it did anything at all. What did I do wrong?

  • Guy Hughes Sep 24, 2015 Link Reply

    Hi Jon
    I fly the Baron 58 as I have it on my ppl license.
    Tried many varieties to try and fix to no avail.
    Back in the “air”
    Thank you.
    Guy Hughes

  • Sibren. May 25, 2015 Link Reply

    Thanks! this worked for me.

  • Jaiden May 1, 2015 Link Reply

    Didn’t work for me.

  • Emilio Apr 15, 2015 Link Reply


  • Aidan Oct 7, 2014 Link Reply

    Thank you so much this was very helpful !!!

  • Firas Mar 26, 2014 Link Reply

    Thank you for sharing your Info helped me a lot

    many thanks

  • charbel Jan 13, 2014 Link Reply

    thank you sir!

  • Sinel Aug 21, 2013 Link Reply

    Thank you very much for this info!!!!!!!

  • Does your blog have a contact page? I’m having trouble locating it but, I’d like to send you an email.
    I’ve got some suggestions for your blog you might be interested in hearing. Either way, great website and I look forward to seeing it expand over time.

  • Kees Feb 24, 2013 Link Reply

    I’m not even getting the acceleration pack installed in the first place.
    When it’s almost done it says it can’t find the dem0501.bgl file.
    Been trying for ages.
    No solutions to be found anywhere on the web. except for one German guy having the same issue.
    Just bought this game yesterday, most, most annoying.
    I’m running w7 x64 with a radeon HD7880 card

  • Alex Nov 17, 2012 Link Reply

    Many thanks to you for taking care of posting your solution. I completely agree with your comments about MS and I also agree with Ronald regarding Apple. So, there is no easy way!
    Best regards!!

  • Clemens May 9, 2012 Link Reply

    Pal, thank you so much for these tips. I was about to wipe my harddisk and do a full re-install. I have VC 2008 installed (both 64 and 32 bit on my 64 bit Win7) did not guess that VC 2005 was needed. Well at least that fixed it.

    And I agree with every single point of your “rant”. Too true. My wife can attest to me ranting exactly the same things. Still can’t get the picture. It must have been a microsoft automatic security update braking a microsoft system component rendering a microsoft application useless. They do not seem to have any kind of quality management.

    Thanks for the Karma.

  • Josh Apr 9, 2012 Link Reply

    Wow, thank you so much. I have had problems with several programs lately, and installing that file helped massively! Thanks again!

  • David Abreu Mar 26, 2012 Link Reply

    Thanks Brother!!

  • Matthew Feb 24, 2012 Link Reply

    This information worked perfectly for myself!! I just purchased the game running Windows 7 x64, was getting the FSX.exe error all the time, this fixed it. Just so others know, just place the file in “C:\Program Files (x86)\Microsoft Games\Flight Simulator X” even though it is not currently there and it will fix everything.

    • Joe Oct 7, 2014 Link Reply

      Just wanted to say thank you because this solved an issue I was having even though it had nothing to do with Flight Simulator. It was to do with the XTCOM_UTIL thing for updating ESP8266 firmware.

  • Ronald Feb 5, 2012 Link Reply

    these hints are gold worth for me! I had exact those two problems which are solved now! I thank you very much!
    Beside this your remarks about microsoft are what I think too. For these reasons many people go with apple, but there you are captured in a closed system. Apple tells you in a arrogant way what is allowed and what not (i.e. flash player). Because of that I remain with windows with a lot of errors and problems but as a free user which is able to use millions of different hardware and software items with my system.
    Best regards

  • K. L. H. Jan 7, 2012 Link Reply

    And sadly, apparently are past the point of giving a rats backside about what level of quality of product they put the Microsoft Name on..Cmon Bill we expect more.

  • Steve Dec 23, 2011 Link Reply

    Microsoft doesn’t develop flight sim–or really any games for that matter–they only publish them

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