Waiting for Target Device to Come Online

Question

I recently updated to Android Studio 2.3, and now when I try to run the application, the emulator does not come online. It times out after 300 seconds.

Additionally,

Answer 1

Check you don't have the deviced unauthorized, unauthorized devices reply the same error in the Android Studio, check the emulator once is on with the adb command.

$ adb devices

List of devices attached

emulator-5554 unauthorized

If you have of this way the emulator the Android Studio is waiting for be authorized and maybe this can solve the problem.

Authorized Devices

This is a error I have solved in Windows 10 with Android Studio 2.3.3