Waitmutex exited with code 6 (MSB3037)

for me it was I deleted a plugin from the engine and using it in my project

For me it was trying to build it in Visual Studio instead using the Live Coding way, Ctrl+Alt+F11

If you had opened Unreal Editor Plz Close And Try Again Maybe Work.

I have a same problem. Do you resolve this error???

I found out that in my case it was related to a plugin “AccuRig”. When it is activated it generates this error. I deactivated the Plugin and now ue / Lyra is working.

Change in LyraStarterGame.uproject the following lines:
image
from True to false.

This resolved my issue, maybe your issue is related to same plugin or other. Check LyraStarterGame.ueproject which plugin are activated /deactivated. I would deactivate all thirdparty plugins.

Hope it solves for you, kind regards,
Ivan

Hey I know its been a year but im following the same tutorial you are and have the same error, did you ever find a fix?