Original Article: http://stackoverflow.com/questions/4072706/the-connection-to-adb-is-down-and-a-severe-error-has-occured
error: “The connection to adb is down, and a severe error has occured”
Try below steps: 1> Close the Eclipse if running 2> Go to the Android SDK tools directory in Command Prompt 3> type adb kill-server 4> then type adb start-server 5> No error message is thrown while starting ADB server, then adb is started successfully. 6> Now you can start Eclipse again. it worked for me this way, Eclipse should be closed before issuing these commands.