SeeMe broadcast feature is shown as 'Disabled' on Aventura"

I am unable to use the SeeMe feature on my Aventura2 as the Broadcast and Emergency features both show as 'disabled'.

I have an active TwoNav subscription and active SeeMe subscription. I have set up contacts for SeeMe and have used it previously. 

Can anyone tell me how to activate these features, or tell me why they might be disabled?