Nevermind. I was answering his first post, where, if you take a look at his snippet screenshot, the object compared was the player. and he wasn't comparing to zombie object, but to an expression from the system condition. Simply was the position of a zombie refered, but not its instance picked.
If you say system compare object1 to (position where object2 is) it doesn't pick object2. That was my point. So be two objects2, runtime 'crashes' for there is not fixed reference, but several to choose from at the time of setting animation.
System needs to know which zombie are you talking about, for the action itself is setting a different anination to that specific zombie that is near the player, but not the rest. With the previous one, at the pkayer getting close to ANY zombie without picking, system will animate... which one? It doesn't know.
Now I see after your comments, which I apologize not reading before posting, je changed the comparison to the zombie object, so now it's fine. I got late.