Use the "Release Data" pushbutton.

What causes this issue?

You tried to set the substatus to "released".

System Response

The substatus is reset to the previous entry.

How to fix this error?

Release the data by choosing the "Release Data" pushbutton.

Procedure for System Administrators

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

Error message extract from SAP system. Copyright SAP SE.