is there a way to unlock campaigns other than finishing human campaign? I cannot play the last mission culling due to some bug (all I see is black screen) so I figured maybe I can just skip it and continue with campaigns... can I? Thanks in advance!
You are in luck! Blizzard has been including cheat codes in its games since the original Warcraft: Orcs and Humans.
Among the cheat codes available for Warcraft III is the handy level-select cheat:
The "Motherland" "Race" "Level" cheat is what you're looking for, so to skip to the beginning of the undead campaign, enter any campaign mission, and enter the following in the chat box (accessed with the enter key):
And you should be well on your way to Deathknight-ing it up with Kel'thuzud.