Hi panospap,
Currently, this JA Social template is working well with Kunena version 2.0, we’ve not updated Kunena to 3.0.1 yet.
At this meantime, you can try with this suggestion:
– Open file:
componentscom_kunenatemplateja_socialhtmlcategorydefault.php
– Underneath this line
defined ( ‘_JEXEC’ ) or die ();
Add this line:
require_once(KPATH_SITE.’/lib/kunena.link.class.php’);
Then clean JAT3 cache and let me know how it goes.
Once again, this template is not updated for Kunena 3.0 so I recommend you to use default template of Kunena instead of social template ( in backend > Components > Kunena > Template manager)