SureAI

Hellow

So I am in Zerobilon in the room where I defeated the boss (a Guard-Mage I think) and then I pressed those two blocks and a portal appeared. However, something is blocking the way to that portal and I don't know why. It is some sort of an invisible wall
But I don't know what to do, so any help would be very appreciated

Oh and also congratulations with the great game you guys created, Nehrim is a very good game!