In ESF 1.2.3 (All i'm using additionally is UM-wFs_ModelPack_for_ESF) and when i start up the server, i can select my character and after that it freezes while the topic title message is on the screen. I end up End Task'ing it. Any ideas?
Game freezes at "Establishing Network Connection"
First thing you might try is uninstalling ESF and deleting the files in the ESF folder, and then making a clean install (without the pack). If it then doesn't work, come back and tell us. Meanwhile you can also tell us your computer's specs and operating system.
