Xamarin Android (Visual Studio 2015) Could not connect to the debugger

Error accepting stdout and stderr (127.0.0.1:8896) Address already in use

This has been reported to Xamarin as Bug 34476.

I had same issue and I was able to connect debugger by following this:

http://dotnetbyexample.blogspot.cz/2016/02/fix-for-could-not-connect-to-debugger.html

In short:

• Disable "Use fast deployment (debug mode only)" in Android project -> Properties -> Android options -> Packaging

• Enable "Migrate to a physical computer with a different processor version" in Hyper-V manager go to VM -> Settings -> Processor -> Compatibility

For me, this turns out to be an issue of DELL laptop running on Windows 10, after I rolled back to Windows 8.1, it works fine now