I can't build my Unreal Engine 5.6 project

Development Platform & Builds
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For context, I recently deleted vs2022 (I know this is were I screwed up) in favor of vs2026. The main issue is that when I know try to build a UE 5.6 project, it gives:

11>Microsoft.MakeFile.Targets(44,5): Error MSB3073 : The command ""C:\Program Files\Epic Games\UE_5.6\Engine\Build\BatchFiles\Build.bat" OrnamentEditor Win64 Development -Project="C:\Users\[Redacted]\[Redacted]\Unreal Projects\Ornament\Ornament.uproject" -WaitMutex -FromMsBuild -architecture=x64" exited with code 6.

I have no idea how to fix this, and it would be nice to know if anyone has encountered this issue. I’ve tried the following:

  • Downloading vs2022 (did not work)

  • Reviewing that MSVC v143 is installed ( I have two currently installed:

    • MSVC v143 - VS 2022 C++ x64/x86 build tools (v14.38-17.8)

    • MSVC v143 - VS 2022 C++ x64/x86 build tools (v14.44-17.14)

  • Repairing vs2022 (did not work)

  • Repairing vs2026 (currently in the process)

  • Deleting the intermediate, binaries, and .sln file (did not work)

Any help would mean a lot.

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Hello there @MataLaCucaracha!

Yeah, that definitely won’t work, as Unreal Engine does not support Visual Studio 2026 at all. The latest versions of UE work with VS 2022 only:

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Now, your current setup has elements from both installs mixed together, resulting in the MSB3073 error you are getting, meaning the engine is unable to find a compatible compiler, or is trying to use the VS2026 compiler, and failing to do so.

So, the best path here is a clean slate approach. First, uninstall all versions of VS, following the instructions here (please make sure you run the InstallCleanup.exe tool):

After that, proceed with the installation for VS 2022 and all its components, with their required versions, which can reviewed in the doc below:

And once the installation is completed, the remaining step is to force UE to detect the changes, which involves clearing your project’s cache again.

As you did before, please navigate to the main directory, and delete folders Binaries, Intermediate. Saved, and DerivedDataCache. Then, locate your .uproject file, right click on it, select “Generate Visual Studio project files”, and allow your project to rebuild, hopefully with no more errors.