QFE for the 4.0.2 Hotfix
If you are using the latest hotfix for this engine version and experience the issue described below, download and run this ‘quick fix’ to resolve the issue.
Download 1: http://cdn.unrealengine.com/qfe/QFE-FromCL-2034640-Shelve-2048959.zip
Download 2: http://cdn.unrealengine.com/qfe/UnrealEngine_QFE_2039063.dmg
Notes: When you get them, install Unreal Engine app from UnrealEngine_QFE_2039063.dmg to your /Applications folder, then open Terminal app and type:
-noselfupdate argument is important because without it the app would update to official version that doesn't work for you. After you download the engine using Unreal Engine app, unzip QFE-FromCL-2034640-Shelve-2048959.zip and run the patch installer it contains. After that you should be able to use the editor etc. You can start the editor by launching it directly: /Users/Shared/UnrealEngine/4.0/Engine/Binaries/MacUE4Editor.app.