Thanks for the FTP credentials. We were able to verify that you're using the latest version of the Open Graph - K2 plugin and it correctly has a check to determine if the current view is the "edit" view. If so, the Open Graph plugin shouldn't be executing line 46-52 in that file, which are the ones that are throwing the error on your site.
Can you let us know specifically what you're doing? Are you simply clicking the "Submit new item" link and it's showing those errors? Is it when you save the page that the error occurs? Also, please provide an exact relative URL (domain not required) of the page with the problem, like /index.php?option=com_k2&view=item&task=edit
In general, we do a lot of testing with K2 under different circumstances. We also have many, many users who use JFBConnect and K2 together. In no cases have we had this issue reported, so we're a bit dumbfounded.
Some other quick things to test:
* Disable all caching on your site
* Disable SEF URLs either in Joomla or a 3rd party extension
** this should be done to provide the relative path above as well
** If you are using 3rd party SEF extensions, let us know what they are
Once we get all the details above, we'll gladly investigate further.
Finally, right now we just have FTP access. If you can provide a super admin account as well, that would help us get some of the details requested above.
Thanks,
Melissa