new user, new campaign

I am trying to create a campaign and have filled in all the boxes except the advanced. It won't let me create it. What do I need to?

Make sure you've selected a character sheet type to use.

Make sure you add [ + ] the character sheet, selecting it is not enough.

From my experience, if there is an official character sheet, I would add that and the custom option (as some players find really good custom ones)