First, that IP doesn't look like an elastic IP address - did you associate your elastic IP with your running instance? (right-click over elastic IP and select "associate")
I was able to duplicate your error - did you change the hostname as instructed:
Changing Default Hostname (required)
As mentioned in the previous section, Amazon does not reveal the external IP of the instance to the running OS. For this reason, you will need to login to the Web Admin UI and configure the Hostname parameter manually (inside the Server Settings section). You may either use an IP address or a hostname here, although it is strongly recommended that you use a hostname since your clients will depend on this setting to be able to know where to connect to.
Note: If you leave this setting as the default, NONE of your clients will be able to connect to your VPN server since by default it is set to a non-routable (private) IP address!
Even if you perform the above step, you will still get the error I think because the connectivity test is looking for an FQDN. As long as you change the hostname to your public IP it will work - I have confirmed this many times.
