You’re using old theme and plugins versions. Please update them.
Don’t forget to make backup your site before updating.
Here is video tutorial how to update theme: https://www.youtube.com/watch?v=KdWESIIPU1k
You can download the latest plugins versions at this link http://www.8theme.com/download-plugins/ ,
enter your purchase code of the theme to get the plugins.
After updating theme and plugins try to disable third-party plugins, maybe one of them caused issue.