Unable to resolve superclass of Landroid/support/v4/app/Watso when using ActionbarSherlock on ADT 22

Exception when you launch app:

W/dalvikvm(24464): Unable to resolve superclass of Landroid/support/v4/app/Watso n; (147)
W/dalvikvm(24464): Link of class 'Landroid/support/v4/app/Watson;' failed

After ADT version 22, Android changed the dependency of build library, when you doing compile, external libraries will no automatically embed in the your final APK.
Here is a workaround:

1. Go to your Eclipse Project Properties
2. Java Build Path->Order and Export
3. Check 'Android Private Libraries'.