I just wanted to ask, is there any way to make "c_content" visible? I just added some contents to NPC models (like in the AI workshop from AUM). But I want them to be visible.

from the manual: c_content works only in no-mesh levels and AABB collision system. Don`t use it in newer (A7) projects.
Search for "in_passable" and "on_passable", maybee you can use this?

"in_passable" is not working, since A7. I just wanted to make obstacle avoidance with them. So there is no way to make them visible, isn't?

you can ent_create an entity at your c_content position and only keep it visible for a frame - that's what I do.