Weird catagory sort error

[Vyst]

Every time I try to go into a category (there is only one) via the sidebox I get this error message

Filter Results by:
Warning: main(includes/modules/FILENAME_PRODUCT_LISTING_ALPHA_SORTER.php) [function.main]: failed to open stream: No such file or directory in /homepages/11/d174087494/htdocs/rentnroll/includes/templates/template_default/templates/tpl_index_product_list.php on line 60

Fatal error: main() [function.require]: Failed opening required 'includes/modules/FILENAME_PRODUCT_LISTING_ALPHA_SORTER.php' (include_path='.:/usr/local/lib/php') in /homepages/11/d174087494/htdocs/rentnroll/includes/templates/template_default/templates/tpl_index_product_list.php on line 60

All products, and new products links work fine...it just seems to be a catagory problem

Note: I've installed the "Column product listing contribution", but i've tried to remove it and I still get the same error (I didn't test before i put it in though to see if the contrib may have caused it)

Any ideas?

[Ajeh]

You have half upgraded your shop ...

Both the files and the database must be upgraded ...

I am not sure what files you did not load to the server, but for sure you did not update the:
/includes/filenames.php

Compare your site to a clean Zen Cart v1.3.5 download and see what else may not have been updated correctly ...