Data is going to be archived after deleting this field.

What causes this issue?

You are about to delete a custom field. Please be aware, that during
import of your deletion into productive system, all data stored in this
field will be archived for 18 months. Afterwards the data will be
deleted permanently.

System Response

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

How to fix this error?

If you want to restore the data of a deleted custom field, please open
an incident for the component BC-SRV-APS-EXT-FLD within 18 months of
deleting the corresponding field.

Procedure for System Administrators

Error message extract from SAP system. Copyright SAP SE.