Error loading in Xamarin Forms PCL

Question

I created a new solution Xamarin Forms PCL, and in debug mode I checked the option Enable ProGuardand I selected Linkingcomboxbox for Sdk and User Assemblies. Now I run my application on android, after which it shows me an error in the MainActivity.cs class and in the line

LoadApplication (new application ());

Error: Unhandled exception: System.NullReferenceException: object reference not installed in the object instance.

I am doing this due to the reduction in the size of my release application, and I need to change the release mode for debugging to check what happened.