SU-PQR2147943860 - Failed to install prerequisites

After handling several errors with the installation, following instructions from older posts, I tried to install the Epic Launcher with the “-SkipBuildPatchPrereq” parameter to skip the check that brings the infamous SU-PQR1603 error.
Now the Launcher is still unable to start due to error SU-PQR2147943860.
I have tried the obvious possible fixes: admin rights, permissions, compatibility, experimenting with Visual Studio and DirectX.

All ideas are welcome!

i am having the 1603 issue, im currently talking with epic to get it sorted but its been like a week and we cant work it out, im now on my 3rd person as they cant work it out hahaha
the skip build patch prereq didnt work for me.
they had me try permissions, install vs versions, delete appdata and uninstall.
no idea what it would be, surely a windows issue right?
i have minimal knowledge on it all.
i played around in the files, only thing i could see was that when i right click on the shortcut and look at the target path it has win32 not win64…my thoughts are this is wrong as my system is 64.
but also think that 32 stuff can run on 64 so maybe not an issue after all.
im also missing win64 folders in a few other locations where win32 folders are.
i did get one other error once which was SU-PQR32

The version I have seems to be 32-bit, too. Still I am not sure what versions exist, because the website of the Launcher does not give a choice to see previous/alternative versions. The documentation is so incomplete, it is practically not existant.

After several days of experimenting, including 3 full reinstallations of the Launcher and after contacting 3 different support agents, nobody knew what causes the problem. To my current understanding, the variety of problems that occur when installing Unreal in different systems, starts from the dependency hell of Microsoft’s frameworks.

I finally built Unreal Engine from source, using Visual Studio. If you have similar problems and you have already tried every possible fix that you can find online, you can compile from source following these instructions (and also these). Yet, you will not be able to install the Launcher, thus I will not mark this post as an answer, and to update the Engine you will have to build the whole VS project again. Compiling from source requires a GitHub account and multiple versions of .NET runtime, .NET Core SDK and Microsoft SQL Server. If Visual Studio brings up errors, check if you have all required versions. You can avoid installing the GitHub client and download all source in a zip file from the website, when your GitHub and Epic Games accounts are linked. After the build is complete, you will have to manually decide which files to keep from all your downloads-built projects. There are also precompiled versions of Unreal in torrent sites, but experiment at your own risk!

Note that all my experience comes from installations in machines with Windows 7 x64 (the latest version of DirectX is different for Windows 10). Now, the latest version of Epic Launcher is 10.2.2 and Unreal Engine’s is 4.22.3.

Support gave me a list of the required Visual C++ Redistributables (runtimes). At the time of writing there is no public list of dependencies in Unreal’s website, so I quote them. The list does not contain all dependencies (see above for .NET etc.) You need both x86 and x64 versions, regardless of your architecture:

  1. Manually download and install DirectX from here
    (Download DirectX End-User Runtimes (June 2010) from Official Microsoft Download Center)
  2. Install Microsoft Visual C++ 2010 Redistributable Package (x86). (https://www.microsoft.com/en-us/download/details.aspx?id=5555) and Microsoft Visual C++ 2010 Redistributable Package (x64) (https://www.microsoft.com/en-ca/download/details.aspx?id=14632) For Step 3, 4, and 5, please install both vcredist_x86.exe and vcredist_x64.exe.
  3. Install Visual C++ Redistributable for Visual Studio 2012. (Download Visual C++ Redistributable for Visual Studio 2012 Update 4 from Official Microsoft Download Center)
  4. Install Visual C++ Redistributable Packages for Visual Studio 2013. (Download Visual C++ Redistributable Packages for Visual Studio 2013 from Official Microsoft Download Center)
  5. Install Visual C++ Redistributable Packages for Visual Studio 2015. (Download Visual C++ Redistributable for Visual Studio 2015 from Official Microsoft Download Center)

NOTE: You cannot use the Marketplace without the Launcher. If you compile from source and you only have the Editor installed, you will not be able to download anything from the Marketplace.
The website of the Merkatplace allows you to see available content, but not download it.