I am a PC user on windows 8.1 and have logged into my account (two other accounts, when family logs in, they do not have this error or issue from Photo Gallery) and click two pictures from Photo Gallery 2012 into my Facebook account, then click connect to Facebook and it comes up with this error:

When two other family members share pictures through Photo Gallery on the same PC, while logged into the PC through their login, they do not have this issue. I am logged into the PC with an Outlook.com email address and have logged into Photo gallery also with that same account and trying to upload two pictures to Facebook.