The time sheet (CATS) is used for confirmation &1/&2

What causes this issue?

You tried to cancel a confirmation, which was created using the time-
sheet, using the standard confirmation transaction.
This cancellation can lead to inconsistencies, as the CATS document
table is not adjusted.

System Response

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

How to fix this error?

The error message can be configured in Customizing under <LS>Plant
Maintenance and Customer Service -> Maintenance and Service Processing
-> Maintenance and Service Orders -> Message Control</>
If you get an error message, cancel the confirmation using the time-
sheet.
For a warning message or an information message, you can also perform
the cancellation using the standard transaction.

Procedure for System Administrators

Error message extract from SAP system. Copyright SAP SE.