The contact details links you can put in to have your Google+ and YouTube profiles linked under your avatar don't seem to work if it is a newer account. Now that Google+ is required for newer YouTube channels, you are no longer able to create "youtube.com/user/yourname" URLs. Same with the old Google+ vanity URLs. So anyone who created those accounts after the switch over can't take advantage of linking them under our avatars. The new Google/Youtube URLs that you are given are just a series of numbers, letters, and symbols that you are randomly given after "/channel/" for YouTube or "plus.google.com/" for G+. Your contact field will not accept it because it doesn't fit the old URL format. So, for example, my new YouTube channel was given the URL: "www.youtube.com/channel/UC93-_VBbf_yfg5nEkhepv-g". YouTube no longer allows you to change your URL, it is just that random series of characters - which your profile editor for the forums won't accept as a valid YouTube path. Just an FYI.