Zoho Meeting Desktop Plugin - does not sign in

Zoho Meeting Desktop Plugin - does not sign in

I am wondering if some one can help me troubleshoot an issue - I am no longer able to launch a Zoho Meeting via the Desktop Plugin (or the meeting.zoho.com website)

Per the attached JPG, the desktop plugin will stall at the signing in screen and if I close this screen and try to launch meeting from the web, I get a message that tells me: 

"Another instance of Zoho is running. Click Yes to close existing instance and continue"

At this point, even after I clik "YES" to end existing instance and continue, the meeting app still does not launch...

Please help!