Macbook doesn't accept password after sleep

After upgrading to El Capitan, my Macbook Pro will not recognize my login password after the computer goes to sleep. It also will not recognize the password to unlock System Preferences. When this happens, my only option is to shut down the computer. After restarting, the system recognizes the password.

I've tried booting to Safe Mode to delete any cached data that may remain from the system software upgrade, but that didn't resolve the issue.

I've searched on multiple Apple community sites and have not found any recent examples of this situation, so any guidance is greatly appreciated.

Thanks in advance for your help.

Paul Thomas

MacBook Pro Retina, 13-inch, Mid-2014

OS X El Capitan, Version 10.11