The system cannot delete enhancement &

What causes this issue?

This enhancement has been migrated. To enable all the projects
associated with it to be converted, it must be transported.

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

System Response

The system cannot delete the enhancement.

How to fix this error?

Procedure for System Administrators

Error message extract from SAP system. Copyright SAP SE.