What are pairs?

I have this error:

Internal Error: Too many pairs created, new pairs will be ignored. This is perhaps due to an excessive number of objects created at one location.:

UnityEditorInternal.InternalEditorUtility:HierarchyWindowDrag(HierarchyProperty, Boolean) UnityEditor.DockArea:OnGUI()

I was wondering what are pairs and what is considered excessive?

EDIT:

I found this in the Editor Log:

Unloading 215 unused Assets to reduce memory usage. Loaded Objects now: 24475. System memory in use: 335.8 MB. Unloading 6 Unused Serialized files (Serialized files now loaded: 2 / Dirty serialized files: 2) Updating assets/buildings/residence/4 story apartment.prefab - GUID: dc87e925ac217eb438fcd069893e5b66... done: hash - 4eef91ee15929cb2dc4df6d3a026968a Updating assets/buildings/transport/fuel station.prefab - GUID: 04fb481b4535a7a4da851742d77294a8... done: hash - ad62f89ca60b828870e8bdcf87c97cf6 /n

Therefore, their "update" converted my prefab into a single cube. I have made extra backups of my prefabs; just in case...

This error comes from PhysX’ collision detection code, which has limits on how much geometry it can handle in a space. It is an error generated by the PhysX library, so not something we can do anything about in Unity. That said, you probably just have too many colliders in one space, which is probably not what you intend anyways, so just fix that, and you should be fine :slight_smile:

I was getting this error and I fixed it by re-building one of the meshes I had. When I replaced all the mesh colliders in the scene with some of the default primitive colliders Unity provides, like the cube or sphere, the error went away. I’m not sure what was wrong with the mesh to begin with though. I think somehow the mesh collider didn’t get created properly, and caused physx to go crazy. This was a very annoying and unclear error message.

If you’re getting this error with only the Unity provided primitive colliders, perhaps this solution doesn’t apply to you.