"Unable to connect to public sessions. Please check your NAT type" error when playing online?

I have played a couple of games using the online games options in Watch Dogs, however today whenever I try to join a game I get the error "Unable to connect to public sessions. Please check your NAT type" as follows;

My current network configuration is with me behind a router with UPnP enabled but for diagnostic purposes I have tested this both with my PC in the DMZ with no firewall enabled and using PPPOA with no firewall enabled so this doesn't seem to be an issue on my end.

Since this was working and no settings have changed on my end, what could be the cause of this error? Are there any suggested settings that I should apply to resolve this problem?

I disabled every network adapter I had installed except for the one required for internet access.

I had VMWare Workstation installed, the adapters of which seemed to be the culprit.

I don't recommend forwarding ports unless you're aware of the security implementations of doing such (especially :80 and :443).

I found one solution that worked for me.

In the GameProfile.xml file I changed EnableNatTraversal from "1" to "0". On Windows 7 the configuration file can be found at Documents\My Games\Watch_Dogs{SOME_ID}\GameProfile.xml On other Windows versions it is probably located somewhere in you "My Documents" folder.

SOME_ID is just a folder with a GUID like name. (If you have multiple folders, try to look in all of them)