Well, I have tried to install that plugin on my test environment, but there was no error unfortunately. Both the search and the plugin were working correctly.
It might be related to your specific server and site configuration, I'm guessing.
I've tried to change the plugin configuration a bit to see if it changes anything, but no crash and nothing on the error log indicating any issues. Based on this I have no idea to be honest with you.Best,
If you like my products, don't forget to rate them on codecanyon :)