Ok I found the 404 Issue. The Default View is Set to List View, but List View is Also Deactivated.
To fix that go to:
Events > Settings > Display Tab > Enable event views
Make sure List is checked.
You are going to have to change the Event Template back to the Default Event Template on that same setting or the Event Views will just be a block of text.
This is the setting for reference:
Events > Settings > Display Tab > Events Template > Default Events Template
Save those changes and that brought back the Views.
Let me know if that helps.
Cheers