Sorry I missed this post, are you still having this issue?
The only clue I can see from your video is that there are a lot of Admin Notices warning about output buffer handlers. I would suggest that you start there because it cannot be good for your admin pages (especially my plugin’s scan page) to be running through a custom output buffer handler. If you deactivate all the plugins causing those warnings and the scan still does not start then you will need to look in your error_log file to see what is causing this (your video was not long enough to see if the page would eventually load with some error message).
Please let me know if you need any more help with this issue. Also note that a direct email to me will usually get you a faster response 
