Resolve Joomla com_jsn PHP Error

I'm encountering an issue with Joomla com_jsn component; it's giving me PHP error messages. Specifically, this pertains to a "Deprecated function message". I'm seeking a professional with proficiency in Joomla and PHP, especially experienced in troubleshooting and rectifying these types of issues - the ideal freelancer should be able to promptly identify and fix the problem. Quick and effective resolution is paramount for the continued smooth operation of the website.