[Plugin: Facebook Page Publish] New Facebook returned error

A plugin installation working perfectly until yesterday returned a new error:
Facebook returned an unexpected error: Error validating access token: Session has expired at unix time 1341679502. The current unix time is 1341909206. Try to resolve this issue, update the plugin or inform the author about the problem. [Error occured at line 347]
I don’t know what it means.
The button “grant access right!” now is red and remain red after clicking.
Clicking to grant permission now give this error:
Some or all access permissions are missing. Please click the button Grant access rights! and authorize the plugin to post to your Facebook profile or page.
[Error occured at line 774]

Your page or profile’s access permissions could not be verified.

http://wordpress.org/extend/plugins/facebook-page-publish/