I have problem with instaling custom language pack. Also, I tried different instalation but always show some errors.
First I try to follow instructions from:
http://www.zen-cart.com/wiki/index.php/Languages
But in categories there is no "Category" headline, it show BOX_HEADLING_TREEMENU, and also I have notice few errors.
Than I try to install "simple" custom language (Serbian):
includes/languages/<your language>
includes/languages/<your language>.php
But when I select that language I just get blank page, and must wait until session over (my default language is English), and then I can see site again. I check all path and it is ok, but dont know why this problem persist?

Thanks in advance.