Hi, sorry for this inconvenience. We're investigating the issue. As Michelle said it's on Facebook's end. Recently FB has done big number of huge changes to theirs API reducing some of the past options due to privacy policy changes. Our engineers are keeping eye on the issue and working on the best possible solutions. We'll keep you updated about the progress.
We all hope that this little obstacle won't get into your way of having fun on BookLikes. You can still invite your friends with the Invite box, it's available on the
Friends page, Invite friends tab. Paste the e-mail address and hit Invite - your friend will receive an invite e-mail from you to check out BookLikes.