The problem is that the same search instance is on that page more than once – which is not supported by the plugin version that you are using.
I suggest you to update to the newest version (by downloading the package again from codecanyon).
The steps for safe updating you can find here, please read them carefully: http://wp-dreams.com/knowledge-base/updating-from-older-versions/
After upgrading the problem should disappear.Best,
If you like my products, don't forget to rate them on codecanyon :)