Assembly order/network & could not be marked for deletion

What causes this issue?

You canceled a sales document position or removed the prerequisites for
assembly.
The corresponding assembly order/network could not be automatically
marked for deletion due to its status.

System Response

The assembly order/network has the latest valid status.

How to fix this error?

Edit the assembly order/network in the appropriate maintenance
transaction and note the log written when you manually trigger the
function "Set deletion flag".

Error message extract from SAP system. Copyright SAP SE.