How to fix Side by Side Error when trying to run the League of Runeterra installer

Legends of Runeterra (LoR) is available for mobile and PC devices since last April 30th. This new title from Riot Games is a strategy card game, based on the League of Legends saga, with a turn-based dynamics, very much in the style of Blizzard’s Hearthstone. You can download the installer from the official LoR page, however you might be unlucky (as it happened to me) getting a side-by-side configuration error when trying to run the .exe file. If you have encountered this problem, do not worry, below you can find the solution.

Fixing error ‘side-by-side configuration is incorrect’

After running the Legends of Runeterra installer downloaded from the official website, I received the following error message on Windows 10:

“The application has failed to start because its side-by-side configuration is incorrect. Please see the application event log or use the command-line sxstrace.exe tool for more detail.”

Right away I opened my control panel to check the latest Visual Studio 2019 C ++ redistributables versions I had installed and search for them in the official Microsoft website to reinstall them. In my case, this did not resolve the issue, so I had to check the Event Viewer to read the error description. You can find the Event Viewer easily by searching Windows for the application name.

Once the Event Viewer is open, select the Windows Logs option on your left and then enter to section Application. There you will be able to locate the last SideBySide error caused by your attempt to run the League of Runeterra installer.

If in the General description box of the SideBySide error, you get this invalid XML syntax message, then you have downloaded a corrupt version of the LoR installer file directly from Riot Games official server:

“Activation context generation failed for ‘D:\downloads\Legends_Of_Runeterra_Installer.exe’.Error in manifest or policy file “D:\downloads\Legends_Of_Runeterra_Installer.exe” on line 0. Invalid Xml syntax.”

You can corroborate this, checking the XML view of the error in the Details, which should look like the following:

- <Event xmlns="//">
- <System>
  <Provider Name="SideBySide" /> 
  <EventID Qualifiers="49409">59</EventID> 
  <TimeCreated SystemTime="2020-05-05T03:54:01.645945300Z" /> 
  <Security /> 
- <EventData>
  <Data /> 
  <Data /> 
  <Data /> 
  <Data /> 
  <Data /> 
  <Data /> 
  <Data /> 
  <Data /> 
  <Data /> 
  <Data /> 
  <Data /> 
  <Data /> 
  <Data /> 
  <Data /> 
  <Data /> 
  <Data /> 
  <Data /> 

Until then all I could think of to do was reporting the bug directly on Riot Games’ official LoR support page. And after 24 hours they answered me the following message:


Please I will need to update all your Windows drivers first with the help of Windows updater

Then please I need you to do a repair of your OS with the help of the following guide

After performing these steps the problem should be solved if not, please write again



Player Support

To save you some time, I tell you that none of that works if you’re having the same invalid XML syntax error message that the Event Viewer reports. If your error message is different, then it is worth taking the time to follow those steps that Riot Games support recommends.

Finally, on my own I checked multiple sources on the internet, until I came across a Reddit post with people reporting the same nature of the bug but with the Valorant beta installer, a new Riot Games shooter in development.

In that post several people were getting the same side-by-side error while executing the installer, with the same invalid XML syntax error description. Then I noticed some of them saying that downloading the installer from another source, or from another Internet access, could fix the problem.

So, I realized that the source of the bug was that the downloaded installer file was corrupted for some reason. Probably it has something to do with the method of generating and delivering the installer file from Riot Games servers.

At that point, I just had to try downloading the file from another connection. So, I asked a friend to download the Legends of Runeterra installer from the official page and then send me the file.

After receiving the file that my friend downloaded, the first thing I could notice was that the installer had the Runeterra ‘R’ logo, while the installer that I was getting from the download had a generic .exe icon. That wrong icon is another indicator that the installer file is corrupt.

I reported the solution of this problem on the LoR support page and they thanked me for sharing the solution, as several people have apparently been getting this same glitch generated by downloading corrupt installer files.

Finalmente, pude instalar el videojuego y ya estoy disfrutando de unas emocionantes partidas de Legends of Runeterra. Hasta el momento se ve bastante completo el juego y la dinámica por turnos tiene ciertas diferencias a la de Hearthstone que hacen que los enfrentamientos sean un poco más balanceados, al darle la oportunidad a cada jugador de bloquear los ataques del contrincante.

Finally, I was able to install the video game and I’m already enjoying some exciting card battles in Legends of Runeterra. So far, the game seems to be quite complete and the turn-based dynamics have certain differences to the ones froms Hearthstone, making confrontations a little more balanced by giving each player the opportunity to block the opponent’s moves or attacks.

Espero que esta publicación haya podido serte útil para resolver tu problema de instalación de LoR, o que al menos te haya puesto en la dirección correcta para solucionarlo. Si fue así, no dudes en compartir este artículo con tus contactos.

3 thoughts on “How to fix Side by Side Error when trying to run the League of Runeterra installer

  • August 28, 2020 at 6:29 am

    Hey there,

    Thank you for sharing your expereince,

    I’m having the the same xml error, but the thing is I am getting that error on lol, It was working fine until i updated the leauge.

    So should I reinstall my game? or should I try reinstalling C++ files.

    Looking forward for your response.

    • August 28, 2020 at 6:43 am

      Hi Abubakar,

      I think you should try reinstalling the C++ redistributables first. And if that does not solve the issue, I guess you should reinstall the game. Just make sure the installer downloads correctly (the League of Legends icon should be visible in the .exe installer file).

      I hope I have been able to help you.


  • May 10, 2021 at 4:38 pm

    honestly, this made completely no sense for me.


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