How do I fix a problem with my alias.php file ?
On Facebook PS Wall Posts or Facebook PS Photo Albums, it is the Token Authentication procedure that will fail in the second step even though you did everything right.
Fortunately, this is easy enough to fix.
1) Download this corrected alias.php file from our server. It comes from PrestaShop 188.8.131.52.
2) Unzip the downloaded .zip file and extract the alias.php file
3) On your server, via FTP, download your original alias.php file from the /config folder, rename it to alias.php.bak and upload it back so as to have a backup
4) Upload the corrected alias.php file
That's it ! Your problems should now be gone.