In order to fix the problem, you will need to contact the people who designed your website. Other users that encountered the same issues, state that the problem is caused by the templates used to design the page. If the website was designed by you, I recommend you try changing the templates. Also, you can try to open the templates folder and to rename them one by one to templatename.off instead of templatename.php. In this way you will see which template is causing the issue.