Can't move object out of a collection

Hi everyone! I encountered a really weird problem in Blender 3.1.0
I created a collection “suit” and moved the object “chest” into it. But the object doesn’t disappear from the root collection, it now appears in two collections at the same time! They are not duplicates or instances. If you delete one, the other one is deleted too. And I just can’t move it out of the “suit” collection any more.

troubleshooting.blend (2.3 MB)

I never had this problem before. Is it a bug?
Anyone can help me? I attached the blend file.

Hey, didn’t you save the file before you put the models in the collection?

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try Right clicking on the lower one and select Unlink. You must have pressed the CTRL button when it was moved to the collection, this creates a linked copy:




Thank you very much! That’s it. :laughing:

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Collections aren’t pure hierarchies. An object can be in multiple collections and always will be the same object… it’s not an duplicate by itself (which could be made single user copy) see: Outliner → Display Mode: Blender File … one object… but more an additional reference (But as @DamianJ said produced by Ctrl-move… )
But if you expand Object Properties → Collections then you can delete it from the collection Suit and it doesn’t disapear in the Scene Collection. After that you can move it into the collection Suit if you want.


Collections represent links to objects and other things as a way of organizing them. More than one collection can therefore link to the same thing. The things in a collection are not “inside of” it. Collections are not meant to be containers.


Thank you for the explanation! Now I see that I didn’t understand collection at all, I’ll study what you mentioned here :slight_smile:

Thank you! Seems I never understood what collections are!
What is an example for a container? An object is also not a container, because it can link to different object data, right?