sougatab,
Not sure why you'd be seeing that. The best guess is that there's a file permission error when trying to extract the downloaded file. We haven't heard of that from other users with this release.
I'd recommend downloading the main package from the
My Subscriptions
area. Then, just install the main JFBConnect component using the Joomla installer. You don't need to uninstall JFBConnect first.
Hope that helps, but if you get other errors, just let us know.
Thanks,
Alex