I'm can go to chat and begin/accept a fight with someone else. It'll go to the "connecting to this port" screen, then eventually it'll tell me to change my ip or port. This happens when I try to host a fight too.

Your help will be very appreciated.

try to restart your computer you come back to the game if this is not helping try to be off the game for some hours
it's happend's sometimes

good thing of u to post this.....i was just about to

go to options and turn on "old connection mode (for firewalls)" in the "network" section ... (should be the very last check-box )

that MAY solve u'r problem...