Can't place any item_ammopack

[CriminalBunny]

I have this problem, whenever I try to place any item_ammopack, hammer crashes for apparently for no reason.
I have no idea what can make this error happen, and as i am kinda new at mapping and all this stuff i don't know how to deal with this very well.

 

[A Boojum Snark]

Hmm, you say you are new, but do you have a really old version of my resource pack installed? That problem cropped up when valve changed something that unprecedentedly resulted in a conflict crash. If yes, either get the latest version from my sig (assuming you still want it), or remove it.