Lost connection when I try to host a terraria world

[Goat_Jedi]

Me and my friend are doing a Vitality mod play through and when I try to host and play it just says "Lost connection" on the T mod loader logo and then a button that says back near the bottom of the screen

[Quandashiuns Brongdale Dingle]

Same here. What's really strange is not being able to join your own server, which should be on the same version of tml with the same modlist. I got it to work briefly after verifying integrity of game cache, but then the next time I hosted I got the lost connection issue again.