There was an error in Security & Privacy preferences
I saw the same error, and I was able to solve this via a reboot--hope that helps!

I can't say for 100% certainty, but I believe I still had some pending updates that had not yet installed: I remember when I was scanning the output of syslog that I also saw some references to a class being implemented in two different files, so I thought that could have been an artefact of an update that had not yet completed. Again, I admit to being a little unsure as to the exact cause of the problem and solution, but this was what worked for me.