UnrealBuildTool fails whenever UnrealHeaderTool is called by mono

I’m going to assume this is a problem with my using of UE4, and not a problem with UE4 itself, hence why I’m posting this in “Using UE4”.

Whenever I try to build any project, I always get the same error:

ERROR: System.ComponentModel.Win32Exception: ApplicationName='/Users/Shared/UnrealEngine/4.8/Engine/Binaries/DotNET/UnrealBuildTool.exe', CommandLine='UnrealHeaderTool Mac Development -NoMutex', CurrentDirectory='', Native error= Cannot find the specified file

I have no idea what causes this, or how to fix this. I’ve spent 2 days searching here and across the internet for solutions, and have found none at all.

I would really like to figure out how to fix this. I can’t build anything with UE4 until I do. I’m unable to get even the built-in templates compiled.