Since I got some errors in my android emulator I manually updated my Android SDK using the command line sdkmanager. It seems the "old" SDK Manager does not support updates anymore. I do not have Android Studio installed (I did not need it since VS2015 installed the platform tools, too). After the update I have to use command line tools for avdmanager and sdkmanager. The "old" AVD Manager and SDK Manager do not work anymore.
However after this update Visual Studio 2015 could not compile my Codova app. I always got the error:
Android SDK not found. Make sure that it is installed. If it is not at the default location, set the ANDROID_HOME environment variable.
Before the app was building correctly.
I did set up the ANDROID_HOME variable to the SDK path (same path as in ADT_HOME). I also tried the suggestion by Abdul Rauf Mujahid to manually edit the regedit.
Both actions did not help.
The ADT_HOME variable is still a valid path.
It seems that others had similar problems Shandu