Winter '21 brought our Customer Community (Experience) to a Halt with no Login Screen!
And we all love puzzles - but this was a doozy (that we should have fixed in January!)
So how to fix it?
Make sure the Community Users have access to all the code on this screen: Apex, VF, Metadata, etc.
I did this by adding to the profile - but finding the code that hits it is a little involved...
It is easier than I thought:
All Communities, Builder (for the one you start with), and then click the Lightning and you will see all the things that you may need to add access for. It is every piece of anything that hits the page. Glorious!
Make sure to look at the components, so that the code they reference is also added.
It needs one permission in System Permissions: View User Records with PII. Otherwise, no one can see the login.