converting managed assemblies to c++ building to ios and unity crashes

Hello, whenever I build my game it crashes specifically when it hits “converting managed assemblies to c++”.
I am trying to build it for ios, I am on unity5 2019, I am on a MacBook air (early 2015), Scripting backend is IL2CCP, if you need any additional information just tell me.
Thank you for your time and I hope you can help me!

After I updated my OSX which lead to updating Xcode and now cocoapod I have the same problem. All I wanted to do is get admob to work like it did before. Now I have a major problem