Unreal Version 4.21.2 Won't Launch on my macbook

Hello,

I am on MacOS Version 10.12.6 and when I got to launch Unreal Engine it will just close my Epic Games launcher and do nothing. When I go to use Unreal frontend to launch I get this error on the picture attached to the question. I figured a reinstall would fix this problem but it did not. I am the Audio guy for my team and I would really not like to Update this mac as it has stable versions of other Plugins for DAWs.

If there are anyways known for repairing library files for MacOS please let me know! Thanks!

I think a download of the MacOS library files should fix this issue

Error for Session using Xcode

Error for Blue Print Session

267798-screen-shot-2019-02-07-at-22234-am.png

In the first screenshot it says that you are missing the MacOSX SDK. Try to intsall that first.