Xamarin Android app crashes in release mode (default constructor not found)

Question

I have a Xamarin app here that runs in debug mode without any problems, but in release mode it crashes instantly saying that a default constructor for one of my pages is missing.

Unhandled Exception:

System.MissingMethodException: Default constructor not found for type PraxisApp.MasterPage occurred

Does anyone have any suggestions why this happens in Release mode?

user_4984832 · Answer

It is most likely due to the fact that it is being stripped by the Mono Linker:

https://docs.microsoft.com/en-us/xamarin/android/deploy-test/linker

Add a PreserveAttribute to the top of your Page class:

[Preserve (AllMembers = true)]
public class MasterPage
{
   ~~~
}

user_7861888 · Answer

Try to add 'PraxisApp.MasterPage;' to your Ignore assemblies (ProjectSettings -> Android Build -> Linker)

Xamarin Android app crashes in release mode (default constructor not found)

2 Answers