Loaded this mod and get redirected to page not found when I try to add a new product. I ran debug file and this error message.

HTML Code:
securityToken|s:32:"42e4e32af6d8dbbc79288302ad6482ec";language|s:7:"english";languages_id|s:1:"1";languages_code|s:2:"en";selected_box|s:13:"configuration";html_editor_preference_status|s:9:"FCKEDITOR";admin_id|s:1:"1";messageToStack|s:0:"";categories_products_sort_order|s:1:"1";display_categories_dropdown|i:0;
I only loaded the book main files. I have been using FCKEDITOR.

How do I fix this? Thanks, Kim