You try to delete a content type in SharePoint 2010 and this is what you see:
Lets review the possible reasons. This error happens when there is a dependency or another object in SharePoint that uses the content type:
- A list/library that is already using the content type.
- Items in the list/library that use the content type.
OK, we dropped the items that use that content type and we removed the content type from the list/library but still we see the same darn screen when trying to get rid of the content type!
What else can possibly use this content type?
The answer is simple: the same items or libraries that you deleted are still using that content type in RECYCLE BIN. Clean up both recycle bins (user and administrator) and then happily wipe off the ugly content type.