As you already know we introduced Facebook authentication within the MashShare dashboard recently. That was our attempt to prevent hitting facebook api limits and a stuck of the facebook share counter.
This was working very well in the beginning but quickly we created more than 8 Million daily calls to the facebook api.
Unfortunately this seemed to be too much and facebook started to reject calls from MashShare running sites from time to time.
As a result the share counter for all sites are affected and stuck when facebook decide to reject the calls.
So starting with update 3.2.7 we removed completely the facebook authentication and integrated a new rate limiter which makes sure that your site does not make more requests per second than allowed for calling the facebook api.
So the following is very important:
Remove the facebook access token from MashShare settings or update to latest MashShare version
If you are using a older version than 3.2.7 you find the access token under MashShare->Settings->Network
Otherwise just update MashShare from your plugin dashboard and you are done.