Fixed.
It was bad data associated with a bad extension that I was hoping to use so people could login with Facebook instead of creating an account. But it didn't work, had to go clean up the data.
Just so everyone knows, once you have an account, you CAN link that account to your facebook login and then login with just your facebook login via OAUTH, if you wanted. That's built into the core phpbb now, so it should work well and it does for me.