Cloud accounts · Adding an account
Why is the "Open browser to sign in" button greyed out?
Short answer: The nickname is usually empty or contains a character that isn't allowed. Use only letters, numbers, spaces or _ - . + @ and don't start with a dash. If that's fine, you may have reached the limit for that account type.
Almost always because the nickname is empty or uses a character that isn't allowed. Type a nickname using only letters, numbers, spaces or _ - . + @, not starting with a dash, and the button becomes available.
If the nickname looks fine, check the account type row you picked: when you've reached the limit for that type, its row dims and can't be selected. Remove an account of that type you no longer need, then try again. See account limits.