Not ready, Please check your connection

I am running TeamViewer 13.0.6447.

When I tried to use Remote Access yesterday with a client who I have gained remote access to a couple of days earlier, I was unable to connect.

Depsite being connected to the internet the error message is 'Not Ready.  Please check your connection'

Can somebody please provide a solution for this as I use this application a lot and it is hindering my work.

TIA