Plutonium

I created a server, but when I try to connect to it from another pc on the same network, it says "Joining game session" and it gives up after a few seconds.
On Plutonium's cmd, a few attempts of connecting to the server show up, and this shows up at the top:
[DW][Lobby] Handling pubfile "largeheatmap.raw"...
But nothing else happens. What could be causing this?