Hi im using
Php 5
Apache 2.2 server
Cent Os 5
Mysql 5
ARTIO JoomSEF v3.1.2

the default install on v3 does not have the mosets tree plugin, i serached the dl section and found the mosets tere plugin as ext_joomsef_mtree-1.1.1.zip i donwnloaded and installed via the admin panel which said SEF Extension Install: Success, now when i go to a mosets tree listing i get the following error
Fatal error: Class 'sef_404' not found in /home/beta/public_html/components/com_sef/sef_ext/com_mtree.php on line 15

anyone know how to fix this

Hello,

Extensions of version prior to 2.0.0 are not compatible with JoomSEF 3.1.x. Unfortunately, we don't offer the Mosets Tree extension for 3.1.x at the moment.

Best regards,
ARTIO Support Team