Knockback from NPC can knock you through walls and gets you stuck
 

Grinding gnomes in Solusek's Eye I noticed they rarely proc a Knockback on me. Sometimes this has knocked me straight through walls into other rooms or corridors, not to mention that it often "pins" me to a wall doing a silly running animation, and I have to do a mix of crouching and feign death for a few seconds in order to get unstuck. Is this classic (I wouldn't be surprised) or perhaps just a client issue?

Should note, knockback will also knock mobs into walls. They can then summon you.

It's awful