Hi!
I have 2 customize items (edited from dwe cube and a sphere item), and I have set up these two items as Quest Aliases for my quest. So they should be Quest Items (I have clicked the box Quest Object for them.)
It works for the cube, so when I pick it up, I can't drop it because it is a quest item. However, it doesn't work for the sphere. I can still drop it. So... it won't trigger the script i wrote because the script doesn't think this item is the right one.
Can someone help me with this? Thanks!!!

You should give more details on how you try to do this

Check to see if the alias is filled. Is it a forced ref?

Ok. My problem is that I put an item on my interior and assign it to Quest Aliases and set it as quest object.
However, when I test it in the game, after I pick it up, I can still drop it. (A quest object shouldn't be dropped)

The alias is filled and point to that object. Every thing is pointed to right position. It works for my another item.

Please help me.

Still not enogh information
First you need to set the checkbox in the alias for it to be a quest item, maybe you forgot.
Then what I actually believe is that you got somehow your item duplicated and you are picking up a different reference.
What I strongly suggest is to print messages from onContainerChanged in your alias and see if you actually manipulate the intended reference.