Thank you for the new credentials. We were able to log in / FTP in to debug the issue.
It appears that the problem is related to access tokens. There are two ways to retrieve the Facebook Page's feed: 1. Using the Page's access token which will return all posts on the page or 2. Using the User's access token, limiting the posts returned to those that the user can see. Depending on how you have your page/admin set up, using the user access token may or may not be a problem with seeing all posts.
Using all versions of the API, we are seeing this problem with the "An unknown error has occurred" when the Page Access Token is used to retrieve the posts. You're using 2.5, but this behavior exhibits from them all as we found with testing the
Graph API Explorer
. This seems to be a confirmed recent bug with Facebook
see here
To workaround this, we changed one line of code on your system in /components/com_jfbconnect/libraries/provider/facebook/channel/page.php. At line 92, we uncommented a line of code that forces the channel to use the user's access token. I could then see the test stream data in the backend now displays the posts.
I would suggest subscribing to the bug that I posted above and posting a comment that your site is affected, but the workaround should hopefully fix your issue.
Let us know if you have any questions.
-Melissa