Fatal error: Call to undefined function

Hi Guys,

I changed my theme, and since changing it, I got the following error:

Fatal error: Call to undefined function ot_get_media_post_ID() in /home/rudico1/public_html/wp-content/themes/hueman/option-tree/ot-loader.php on line 612

To get it, I clicked on ask a question, Questions and Unaswered still works fine.