Trouble in installing the plugin

Today I tried 4 times to install QSM plugin. But after installing it, My website stopped working and an error page appeared that was something like “There has been a critical error on your website. Please check your site admin email inbox for instructions.”

And then I had to delete the plugin file from directory every time.
I also tried to install the plugin uploading zip file downloaded from WordPress. But the same thing happened. Other plugins are getting installed properly.

Thanks in advance…

The page I need help with: [log in to see the link]