Description
In Dashboard > Products Registrations if you click on 'Register Product' you can see an error at the top of the page.
 
Solution
Download the updated version of the file:
http://www.viart.com/downloads/registration_functions-4.0.7.zip
 
Further, extract 'registration_functions.php' into 'includes' folder of your shop via FTP in BINARY mode replacing an existing file. Please do not forget to make a backup copy of the current file in case something goes wrong.