User blog comment:I am the scout here/Goblin army not working?/@comment-6944821-20130322212740/@comment-186.26.112.44-20130329054957

If you still haven't solved this, when you initially summon the Goblin Army, it should say "A Goblin army is approaching from the east/west!" Wait a while to see, and eventually it should say "A Goblin army has arrived!" Go to your spawn to fight it.