Posting here for a lack of where to post. It looks like the Epic Games Launcher app on OS X is built from broken code.
Actual error:
11/12/15 11:59:24.375 AM com.apple.xpc.launchd1: (com.apple.xpc.launchd.oneshot.0x10000014.UnrealEngineLauncher-Mac-Shipping[36487]) Could not find and/or execute program specified by service: 2: No such file or directory: /Applications/Epic Games Launcher.app/Contents/MacOS/UnrealEngineLauncher-Mac-Shipping
(emphasis mine)
You can see that should have been fixed by this commit
I don’t think there’s a pull request I can make to fix this, I think it needs to be cherry picked into whatever branch the download link version is built from and rebuilt. I’m checking out the UE4 source and I’ll build it myself to see if that fixes it.
Or… there’s some weirdness with launchctl having a cache of that name for the oneshot daemon. Which explains why the “answer” post claims it works after a few restarts. I’ll keep digging.