Brief
We have updated the files 'admin_table_categories.php' and 'admin_export.php' for version 3.6.

Description
Product Category export function fails in 3.6.

Solution
We would recommend you to download an updated version of the files from the link below. Further, extract the above mentioned files into the 'admin' folder of your shop. Do not forget to make a backup copy of the current files in case something goes wrong.