Data element & is still being used in table/structure &

What causes this issue?

A where-used list for the data element was executed which determined
that the data element is referenced in tables or structures.

The system issues an error message and will not allow you to continue with this transaction until the error is resolved.

System Response

How to fix this error?

If you want to delete the data element, eliminate the use of the data
element in table fields or structure fields before deleting.

Error message extract from SAP system. Copyright SAP SE.