I'm the system admin for a Community and recently I've started getting this error message by email: 

"A new user's attempt to register at NAME_Portal failed because the value for the profileID attribute is either null or invalid. Set the profileID for new users on the ChatterAnswersRegistration Visualforce page for the site associated with community NAME_Portal or on the apex class associated with the Facebook authprovider."

We don't have Chatter Answers enabled and we don't have Facebook set as an Auth Provider so I'm not sure what's going on there. Additionally, we haven't made any changes to our code recently around the self registration. Any thoughts?

I have a custom tab for a custom object that is used regularly in our org. We are making the switch to Lightning, but I cannot get this one tab to show up in Lightning. It is available in classic and I can access it from the waffle icon in Lightning. Below are some screen caps of me adding it to our Lightning navigation menu. I've set everything else up the same way and it is working fine. Any thoughts on what I could be missing?