Changes to how the Android SDK manages the installed API levels and AVDs.

Changes to Android SDK Tooling

In modern versions of the SDK Tools for Android, Google has removed the existing AVD and SDK managers in favour of new command line interface (CLI) tooling. The former android program has been removed and the the GUI(Graphical User Interface) managers in Xamarin Studio and older versions of Xamarin for Visual Studio will no longer work past verison Android SDK Tools.

Attempting to use the android program via the command line will result in an error message like the following:

The "android" command is deprecated.
For manual SDK, AVD, and project management, please use Android Studio.
For command-line tools, use tools\bin\sdkmanager.bat
and tools\bin\avdmanager.bat

Thus you will need to use the CLI tools to manage and update your emulators and Android SDK.

CLI Tools

The following programs now make up the command line interface for the Android SDK tools:

sdkmanager

Added In: Android SDK Tools 25.2.3 (November, 2016) and higher.

There is a new program called sdkmanager in the tools/bin folder of your Android SDK. This tool is used to maintain the Android SDK at the command line.

You can find out more on the basic usage of this tooling here:

https://developer.android.com/studio/command-line/sdkmanager.html

avdmanager

Added In: Android SDK Tools 25.3.0 (March, 2017) and higher.

There is a new program called avdmanager in the tools/bin folder of your Android SDK. This tool is used to maintain the AVD's for the Google Android Emulator. You can find out more on the basic usage of this tooling here:

https://developer.android.com/studio/command-line/avdmanager.html

Downgrading

You can downgrade your Android SDK Tools version by installing a previous version of the Android SDK from the Android Developer website.

Using the old GUI

You can still use the original GUI by running the android program inside your tools folder as long as you are on Android SDK Tools version 25.2.5 or lower.