[Bug] Cannot delete un-referenced Material Parameter Collection

It doesn’t seem like i am able to delete any Material Parameter Collections that I make even if they are not referenced by anything and have had their parameters cleared. They just keep throwing an error:

MaterialParameterCollection /Game/TheTower/Characters/Goblins/Sets/001_BasicLeather/MATPARAM_GoblinDEfault.MATPARAM_GoblinDEfault is in use.


Running the editor with ‘-NoLoadStartupPackages’ may help if the object is loaded at startup.

External referencers of MaterialParameterCollection /Game/TheTower/Characters/Goblins/Sets/001_BasicLeather/MATPARAM_GoblinDEfault.MATPARAM_GoblinDEfault:
MaterialParameterCollectionInstance /Engine/Transient.MaterialParameterCollectionInstance_7 (2)
0) None
1) [[native reference]]
MaterialParameterCollectionInstance /Engine/Transient.MaterialParameterCollectionInstance_8 (2)
0) None
1) [[native reference]]
MaterialParameterCollectionInstance /Engine/Transient.MaterialParameterCollectionInstance_9 (2)
0) None
1) [[native reference]]
MaterialParameterCollectionInstance /Engine/Transient.MaterialParameterCollectionInstance_10 (2)
0) None
1) [[native reference]]
MaterialParameterCollectionInstance /Engine/Transient.MaterialParameterCollectionInstance_11 (2)
0) None
1) [[native reference]]

Shortest reachability from root to MaterialParameterCollection /Game/TheTower/Characters/Goblins/Sets/001_BasicLeather/MATPARAM_GoblinDEfault.MATPARAM_GoblinDEfault:
MaterialParameterCollection /Game/TheTower/Characters/Goblins/Sets/001_BasicLeather/MATPARAM_GoblinDEfault.MATPARAM_GoblinDEfault [target] (standalone)

Am also unable to delete a MPC. Looks like it is referenced to /Scripts/Engine.

Hi Aidan,

I have reproduced and reported this issue. Thank you for bringing this to our attention.

  • Adam