Making sure that all social properties are authorized is essential. If a property isn't authorized, then publishing, moderation, and many other features of Social don't work. When you authorize a page, you create a token. At least one valid token must be available on a social property for posting to work successfully. Tokens can expire after 60 days, when a user changes their password, as well as sometimes when Twitter or Adobe Social releases an update.
It is important that as many people as possible have current authorization to avoid the issues above. For example, if user A's is the only one to authorize a page and there are no other tokens that could be used. Therefore, if user A's token becomes invalid for some reason, posts fail again for the same error exception reason. However, if six users have authorized a page, then if user A's token has expired, it automatically checks if user B, C, D, E, and F's tokens are valid. Having multiple users tokens greatly reduces the chances of posts failing.
Important: For LinkedIn, YouTube, and Sina Weibo, only the user who added the account can reauthorize it. All other social properties can have multiple authorizers.
If it's necessary to reauthorize a property, all users who can do so get an email notification letting them know (unless they've turned this notification off). You can check your notifications status under Settings > Preferences > Email Notifications > System > Upcoming Facebook authorization expiration. If this box is checked, notifications are sent to the email address listed above.
Adobe has also added handy yellow alerts to help you know when it's necessary to reauthorize a page. Click the Grant Permissions link in the alert to go to the page in question, and click Reauthorize next to it.