If you are in a hospital or clinic with a network firewall it's possible it is blocking access to websites or ports used by Doxy.me to make a successful call. Ask your IT staff to 'whitelist' the following:
Open TCP port 443 for outbound SSL and non-SSL traffic to:
All of the above, and open UDP port 3478 for inbound and outbound traffic to *.opentok.com and *.tokbox.com.
If you are still having issues after trying these steps, contact our support team.