Brief
We have modified the 'admin_config.php' file for release 3.4.5.
 
Description.
If you're were editing something in the file manager, and navigate away by clicking another link in the admin section, the link that it navigates became invalid as it just adds the link at the end of the file extension which wasnt' correct.
 
Solution.
We would recommend to download an updated version of the files from here: http://www.viart.com/downloads/admin_config-3.4.5.zip
 
Further, extract the above mentioned files into the 'admin' folder of your shop replacing an existing one. Don't forget to make a backup copy of the current file in case something goes wrong.