Couldn't find module rules file for module 'JsonUtils'.

Hi all, this has now happened to me a few times, and rather than re-installing again, i wanted to throw this out there…

Suddenly I can no longer create any code projects, rebuild the code projects that i have or generate visual studio files. When I try, I get:

Running C:/Program Files/Epic Games/4.11/Engine/Binaries/DotNET/UnrealBuildTool.exe  -projectfiles -project="Test.uproject" -game -rocket -progress
Discovering modules, targets and source code for game...
ERROR: Couldn't find module rules file for module 'JsonUtils'.

Has anyone else come across this? And hopefully solved it?


This message (most likely) means that a module with that name doesn’t exist at all. But it could also indicate that you have typed it wrong, or if you’re sure it does exist that it may not have a <ModuleName>.Build.cs file.
I haven’t searched for a module named “JsonUtils” but I can’t immediately spot it directly under the Engine/Source/ folder either. However there IS a module named “JsonUtilities”. Not sure what you’re expecting to be in JsonUtils but it may have been moved/renamed to JsonUtilities? So I suggest you simply check it out and if you know what was in JsonUtils before (sounds like you’ve successfully used it before) see if the same is now known as “JsonUtilities”.

Thanks! I narrowed the error down to a third party plugin, and am in touch with the developers. That “JsonUtilities” does sound like the culprit though.