SSL-VPN

Over the past 3 weeks the VPN connection is showing the above error and can’t be stopped until you connect to a Personal Hotspot from a mobile device. This is happening to staff working in all area's outside the Wellsway school campus.
As a admin user I can stop this message from appearing every couple of seconds, but a user can not until they connect to their phone. In the past the VPN connection screen would appear and the user could just minimize it and they could get on with their work. Please could you advise how we can fix this issue.
This problem is stopping the user from being able to work on their laptop as the message wants to be in the foreground all the time.
