Cancelling the production order

Dear experts,

The start date and end date of the

production order are from April 11 to April

12, 2023. However, when the client tries to cancel

the order using CO13, an error message

appears: "Posting period 004 2023 is

locked (check posting date)." The client does not

want to open the period, so I would

appreciate it if you could suggest a

standard procedure for cancelling the

production order that I can suggest incase if opening the posting period is not an option . For example,

cancelling the posted document or

changing the date of posting.

Thank you in advance!