I get a 404 error when I open portfolio item?
This happens because of your permalink structure.
1st try to use default (ugly one) permalink structure to see if it’s working.
If it works, try to change slug of portfolio page. If this doesn’t help, change default rewrite slug for portfolio custom type in includes/bra_theme_functions.php
'rewrite' => array('slug' => 'portfolio'),
After that update permalink settings…