What does that even mean?
If you don't want to read that much, but just want to fix the problem, just read on below under "What can I do"!
The SocialHub uses the Facebook API to communicate with Facebook and the Twitter API to communicate with Twitter. To allow the SocialHub to do this for your site, you first have to give it permission - this is what we call "access token". You do this when you create the channels, when Facebook asks you if you want to give the hub certain permissions.
If the SocialHub emails you saying that the access permission has expired, this can have several reasons. For example, the hub may lose permission if you change your Facebook password, or if you take away permission from it at https://www.facebook.com/settings?tab=applications. The same is true for Twitter.
What can I do?
The channel is no longer displayed in the hub: If no other access token is available
No big problem at all. Just add the channels under Account > Channels in SocialHub and give Facebook or Twitter the necessary permissions. Here you can find detailed instructions
The channel is still displayed in the hub: If other access tokens are still present
Simply go to Account -> Channels in SocialHub, click on the "Add access token" button next to the relevant page and give our Facebook app the necessary permissions. That's it - your access token has been renewed!
If there are still problems, just contact us: firstname.lastname@example.org
That's impractical - why don't you just leave the access token active?
Access tokens are controlled by Facebook, not SocialHub. For example, if someone hacks into your Facebook account without authorization, Facebook automatically cuts the connection to SocialHub. That's actually good.
Sometimes, however, not so useful. For example, I once logged into Facebook while on vacation in Dubai. Facebook saw this as a security risk and sent me a warning email because someone from another country was trying to log into my account. Facebook disconnected me from the hub.
Especially if several employees in the hub are to maintain your site, it is therefore useful to add multiple access tokens. Even if the access token expires for some reason, the page remains linked to the hub.