I had this same problem

http://stackoverflow.com/questions/43294345/visual-studio-2017-xamarin-the-file-obj-debug-android-bin-packaged-resource

First set build output verbosity using

BTW, I managed to find what’s the problem by setting build output verbosity to Diagnostic in Tools -> Options -> Projects and Solutions -> Build and Run which gives a detailed info why the build failed in the Output window.

Then do a search.

In my case I had

Resources\layout\Main.axml(2): error APT0000: Integer types not allowed (at ‘textSize’ with value ’90’). (TaskId:176)

CRAP! I need to change it to 90sp   (Of course)

grr that wasted too much time.