Try adding these permissions: http://guildlaunch.uservoice.com/knowledgebase/articles/437834-why-won-t-the-ts3-widget-show-my-ts3-server-inform
Sorry I should've mentioned that I found that link in another post and have already confirmed that those settings you linked to are enabled. I should also mention that this was working up until (now) three days ago. Occasionally we would see this error then it would clear on it's own. Now not so much.