# Exceptions

This page details asset types and special cases that affect the behaviour of SubAsset Toolbox.

## Illegal asset pairs

Not all asset types can *have* sub-assets, and not all asset types can *be* sub-assets. As you parent/unparent an asset, you might see error messages in one of these cases.

Types that cannot become sub-assets:

* C-Sharp files (.cs)
* Prefabs and Prefab variants (.prefab)
* Scenes (.unity)
* Meta files (.meta)

Types that can't have sub-assets:

* C-Sharp files (.cs)
* Audio Mixers (.mixer)
* Shader files (.shader and .shadergraph)
* Scenes (.unity)
* Meta files (.meta)
* Folders

## Special create asset behaviours

Sometimes, when you right-click > Create an asset while another asset is focused, Unity does something special based on the created/selected asset types. In these cases, SubAssets Toolbox will not add the created file as a sub-asset, but instead respect the default behaviour.

These pairs are:

* When a Prefab is selected, and you right-click > create a Prefab Variant, the newly created Prefab will be a variant of the selected base.
* When a 3D model is selected, and you right-click > create a Prefab Variant, the newly created Prefab will be a variant of the selected 3D model.
* When a shader is selected, and you right-click > create a Material, the newly created Material will use the selected Shader file as its shader.