Q: Beware! This update may break your OS (boot freezes with white blank screen and no login). I spent 3 days trying to fix it and ended up restoring everything from backup! Other users reported the same issue. Apple needs to address this.
This is not a question but a solid statement. Upon applying this update my MacPro stopped booting to login screen. It would just hang with white blank screen. It wouldn't even boot in a Safe mode! Recovery did not help - the same issue remained. I had to restore the whole partition from backup to fix this problem. Other folks reported the same issue. I am not sure if this is related to my ATI HD 5770 graphic card but it seemed very much like this. The OS would fully start but there's no login screen; the only option is to login via telnet/ssh. system_profiler would fail to work either.
I'll wait till Apple does something about this update.
Mac Pro, OS X El Capitan (10.11.3)
Posted on Mar 23, 2016 7:27 AM