The usual reason is that you need an active internet connection for the maps to work. This could mean no internet connection at all or a firewall rule that's blocking something that Tableau needs.
Can you browse the internet from the machine you have Tableau loaded on? If so, is something blocking the ports or protocols that the map service uses?
This link is for Server, but it might help:
yes I can use internet using my WI-FI where I have my Tableau. I have gone through the link you have provided and added the URL in the trusted sites. but still it is not working. Cant understand what is going wrong.