Hello, since Monday 10th June I am receiving this error message whenever I try to use the Gmail Add-In (desktop and Android). Have tried removing and re-adding the Add-In, with no change.
Any suggestions?

Hello, since Monday 10th June I am receiving this error message whenever I try to use the Gmail Add-In (desktop and Android). Have tried removing and re-adding the Add-In, with no change.
Any suggestions?

Your best bet is:
Try these troubleshooting steps, then please create a support ticket: see How to contact our Support Team.
Thanks,
Larry