work-around :
go to base_facebook.php
look for the protected function getCode()
this is the problem.
the $this->state
variable doesn't stay saved for off-site navigation (natural)
replace this:
if ($this->state !== null &&
isset($_REQUEST['state']) &&
$this->state === $_REQUEST['state']) {
with this:
if ($_REQUEST['state'] != '' && $_REQUEST['code'] != '') {
And it's going to work just good
G@bri3l