...
You will need to use System Tables to clear out the Certificate Number.
...
First search the MOD_PROJ table for the matching project number.
...
Delete the value in Aprv_num and save the record.
(NOTE: If you do not have update access to System tables and are a NAPA System Administrator, you need to search for yourself in the TC person module and change your TC group to Aircraft Certification save.
Then logout and restart NAPA)
Go back to regular NAPA Search and search the Project the regular way.
Open the Project certificate summary Detail Certificate Summary tab and use the get Approval Number button to generate the correct approval number. Save the project.
...