I experienced the same issue, and the solution was to download the SDK again from Android: https://developer.android.com/sdk/index.html
I tried to revert the ADT from 22.6.0, which was the one giving this errors, to 22.3.0, but couldn't do it manually. So the solution was to download the SDK again from Android, because ironically, the online version at the time of this answer is still the old version of ADT (22.3.0), which works.
Hope it helps!