Can you help provide some more details about the error you're encountering? Can you let us know:
* What version of JFBConnect is installed?
* What version of Joomla are you using?
* What are you doing when you encounter that page? Is it just going to a certain page in the admin area, or are you trying to do something specific?
Also, if you recently upgraded, can you tell us if this feature worked before, or if this is the first time you're going to the page with this error?