follow these steps:
- Help > Install new software
- Select the ADT update site (there are two, one with Android Developer Tools Update Site - http://dl-ssl.google.com/android/eclipse/ and one with Android Developer Tools Update Site - https://dl-ssl.google.com/android/eclipse/ If one doesn't work, try the other).
- Select the developer tools section and press next.
- You should see a dialog that says "this software is already installed, an update will be performed instead". Clicking ok will lead to 22.6.1 being installed.
check this link https://code.google.com/p/android/issues/detail?id=67325