I don't have a screenshot from the game because it is not in the game. When I add a civilization in the editor and save the new civ disappears. The only way to add a civ is to delete one or modify it to the new civ. Is this a bug or is there supposed to be a limit on the number of civs?

The limit of civs being supported is 31.
If you're going for the 32nd, you have to delete one of the others.