Hi,
Facebook have made many updates in the last year, now in the new Apps it requires "Valid Oauth Redirect URIs" (this was added 6 months ago) and Https (this is something of very new, so our docs does not contain any reference, we will update soon)
before update easy-profile
This is not something that regards Easy Profile updates.
the installation on another website we have still works
This happen because your Facebook apps on this site is a old version (so not require something like https) but it is not yet deprecated (so it works)