I am unable to connect to clients - receiving Connection Lost error

I am unable to connect to clients - receiving Connection Lost error

I cannot connect to any clients via zoho assist. These are clients who have been set up for months for unattended remote access.

I've used updated version of both Chrome and Explorer, but always receive the following error:

Connection Lost! Reconnection attempt under progress...

I've tried uninstalling, then reinstalling, which was unsuccessful.

Some of these clients are behind firewalls, some are not.
    • Sticky Posts

    • Release Notes: Version 1.91, February 2015

      Unattended Access (Beta) is live!   Unattended Access, a feature requested by a lot of our customers is live now. Currently, it's in beta. You can add up to 100 computers per Technician subscription. They can also be accessed by your organization members.  My Computers  list in Zoho Assist home page will  always  display the online status of your unattended computers. You can rename the computers whenever you wish.  Currently, Unattended Access can be configured only for Windows computers. Nevertheless,