+1 it also bothers me if it's a character that's not viewable to minors. I think that message when trying to view an 18+ character would instead show something like "This character is only viewable for users 18+".
I would like to suggest a change to the way that a page shows up when you click on it and don't have permission to view it. Invalid Character to me has always meant that this link no longer works because the page was deleted. I would like to suggest it be changed to "You must be logged in to view this character" for when the character is set to Logged In Users Only and it would read "You must be authorized to view this character" for when the character is set to Authorized Users ONLY or to Specific Lists.
Thank you for reading, if you agree please leave a comment stating that you agree below.