UnrealBuildTool Unable to open log file for writing because it is being used by another process

I found the answer and had a moment of deja vu. You need to turn parallel builds down to 1 in VS. You can possibly get away with more but most likely not.

This will cause it to build slower, but it will actually work. Seems like a crazy thing to not have fixed in 22 versions of the engine though.

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