No CO object is defined for order &

You worked on order &V1&. No CO object has been defined for this order.
Check by displaying the order in table AUFK with the table display
function. Display the object number or object ID in the table.

System Response

A CO-related posting or selection cannot be made without an object
number.

How to fix this error?

The error is probably linked to the import of Release 1.2A and the
conversion of the CO. The SAP System will run normally after the update
is imported and the data conversion is completed.
If the termination occurred at another time, an internal system error
has occurred. Contact the SAP hotline service.

Error message extract from SAP system. Copyright SAP SE.