Android Debugging Failing With "Couldn't connect to logcat, GetProcessId returned: 0" FFImageLoading.Platform.dll.so Not Found

This worked for me :-

Deselecting the 'Use Shared Runtime' in Project Properties > Android Options > Packaging properties

I also had this issue with Android 8.1 and Visual Studio 2017 15.7.4.

There are three steps to got it working again.

1. Under Android Options, go to Advanced and add your device architecture, in my case it was x86_64.
2. Go to Tools -> Options -> Xamarin > Android Settings and enable: Provide debug symbols for shared runtime and base class libraries.

3. And the final step is to delete following Apps from your device:

   • All Xamarin.Android API Support libraries
   • Mono Shared Runtime
   • Your App

After these steps you don't need to disable "Use Shared Runtime" and can Deploy and Debug much faster.