You cannot select assembly order & for deletion

What causes this issue?

Due to the current situation of the document, the system has attempted
to mark the procurement element &V1& with a deletion flag.
This could, however, not be carried out, as the procurement element was
in a state that does not allow the deletion flag to be set.

System Response

The deletion flag is not set.

How to fix this error?

PERFORM DELETION_PROTOCOL IN PROGRAM SAPFV45E
CHANGING &PROT_EXISTS&
ENDPERFORM
IF &PROT_EXISTS& EQ 'YES'
In the <DS:REPO.PPDLSHOW>deletion flag log</>, you can see which error
messages resulted in the procurement element not being able to be
marked for deletion.
You can also see this log if you go from the sales order via the
schedule line screen and the procurement detail screen to the
procurement element, and then choose the function "deletion flag" to
display the log.
ENDIF
Eliminate the reasons that stop you setting the deletion flag, and
repeat the change carried out on the sales order.

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.