Hello,
I tried to create a project in C++, but it displays this error that I don’t understand. It’s not the first time I’ve created a project in C++… (UE 5.3)
Thanks
Hello there @Ebene!
Checking through the community, issues related to “System.ArgumentNullException: Value cannot be null” have been ongoing for a while.
The current workaround involves locating conflicting plugins in your build (anything that has incorrect build.cs files), and removing them from the plugin folder.
Further data can be found the following thread:
Thanks for the reply! I’ve tried removing plugins that were already causing problems, but the error persists… So I decided to install a more recent version (5.5.4) and now I have an error message, but no error in it. The project is not generated.
Hello again!
That is a very peculiar response, the log states the project is being generated, then nothing. There is an element in your install generating a conflict, but it’s hard to locate. At this point, I would suggest a full uninstall/reinstall of all Epic software, along with a refresh for Visual Studio:
- First, uninstall the engine, launcher, asset packs, etc
- Next, open the registry directory HKEY_CURRENT_USER\Software\Epic Games\Unreal Engine\Builds, and delete any build entries
- Finally, delete the folders %userprofile%\AppData\Local\UnrealEngine and %userprofile%\AppData\Local\UnrealHeaderTool
- After that, no elements related to UE should be left in your system
- Now, reinstall UE launcher from scratch, and add any version of the engine you need
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I’ve done everything you suggested, but unfortunately the error message remains the same. I’ve also checked Visual Studio. I think I’ll reinstall Windows…
Thanks for your help and your time! 
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