I have forwarded the port on my router, and also disabled windows firewall. upnp is enabled on my router. NAT is set to Open.
Hammerwatch still won't let me host, and so I've even tried putting my computer on a DMZ, static route, disabled firewall, etc.
Research tells me that this is an issue with most ISPs blocking ports < ~1000, so I desperately need the ability to change the hosting port, or to at least have the default be in the 4000s