Mail Suite Sync Does Not Login

I have installed the Zoho Mail Suite Sync app to be able to sync my Outlook calendar with my Zoho calendar. However, after I enter my email address and password the app seems to freeze. I click "sign-in" and nothing happens. Clicking "sign-in" or "X" to close the app makes a bell sound letting me know I can't click either of those. Then nothing happens. I have to force close the app using the Task Manager to get the app to close. Any ideas on how to fix this? I am using the 64-bit version of the app on a 64-bit windows machine. My Outlook version is 2016.