Since I upgraded from 10.10 to 10.11 Beta (currently on 15A279b), I can't change any system preferences anymore, as the lock does not unlock despite the input of the correct password.
If I click on the closes lock symbol, then the text next to it changes from "click the lock to make changes" to "Authenticating" and I am asked to input my password. If I input an invalid password and click the "Unlock" button, the the password input field just vibrates and stays open, like it used too in previous OS X versions. However if I input the correct one, then the password input box closes, showing successful authentication (the console also logs a successful authentication), but the lock symbol stays closed and the text next to it just changes back to "click the lock to make changes".
Closing open locks works, just opening closed ones does not.
With previous OS X versions I would have run a "repair permissions" in disk utility in case the update somehow set some wrong permissions, but unfortunately the "repair permissions" feature has been removed from disk utility with 10.11 as it would be "no longer needed".
Any ideas how to solve this or a workaround?