[Bug] Can't create a competition using the online editor

I can use the online editor to create all the parts of a competition (the tabs "Participation", "Pages", "Phases", "Leaderboard" are with a green check) but I can't add a new administrator and I can't click on the "Save" button. From what I see on the online editor, all the mandatory fields are filled but I supposed that because the "Administrators" field is not with a green check, I can't save.