Test plan created according to start date/end date/profile

What causes this issue?

The system generated a test plan according to the indicated hedging
profile, start date, and end date.

System Response

To be able to create a test plan, the system needs the designation date
(or the planned designation date if the designation date is not
available yet), the dedesignation date (or the planned dedesignation
date if the dedesignation date is not available yet), and the hedging
profile.
If the designation date or dedesignation date don't correspond to the
<ZH>planned</> designation date or dedesignation date, the test plan is
changed according to the designation date or dedesignation date after
designation or dedesignation.

How to fix this error?

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

Procedure for System Administrators

Error message extract from SAP system. Copyright SAP SE.