Error: This authorization code has been used.

I got this error: … Facebook Platform” “invalid_code” “This authorization code has been used… after I added small update to my app (change App domains from xyz.com to http://www.xyz.com and change contact email) and then I clicked the reauthorized link.

But the odd is when I created new app for another website, this app works. Then inspired by this, I created new app for my http://www.xyz.com but it doesn’t work…

http://ww.wp.xz.cn/plugins/social-networks-auto-poster-facebook-twitter-g/