You are trying to unapprove or delete an asset and get the following error: [Asset Name] is in use and cannot be deleted/unapproved
Marketo assets (such as emails, templates, forms, lists, smart lists, and programs) cannot be deleted while they are used or referenced by another asset. If the error does not specify where the asset is being used or referenced, you can find this information in the Used By tab in the asset's summary page.
For programs, you can find the Used By section in the program's View drop-down.
The Used By section will show where the asset is in use, and you can click on the links to jump directly to that location.
Once the asset is no longer referenced anywhere else in Marketo, it can be deleted. If you are certain the asset is no longer in use but are still unable to delete it, please contact Marketo Support