Xamarin - Cannot create android Black app : “Object reference not set to an instance of an object”

Question

Week ago I upgrade my Visual Studio 2017, and now I'm unable to create an Android app in Xamarin. I have some problems and I dont know whats the main.

When I create the Blank app only the folder is create and I get this error:

    Object reference not set to an instance of an object

As I read here: Object refrence not set to an instance of an object When I create new Android App (Visual Studio) and others posts the solution is upgrade the SDK but I can't even do that because my Tools dont contain anymore Tools/Android...

I also cannot find Xamarin SDK manager in Individuals Components as say here:

https://docs.microsoft.com/en-us/xamarin/android/get-started/installation/android-sdk?tabs=vswin

And also I get these errors in Tools/Options/Xamarin:

The package "DesignerPackage" did not load correctly.

The package "MonoAndroidDesignerPackage" did not load correctly.

I reinstalled Xamarin, Restore and Repair Visual Studio and nothing works.

Answer 1

I had a similar problem and it was fixed by downloading JDK8 (I had JDK9 on my machine and had to delete it). What version JDK are you using?