Program line processing control may be configured as either ‘Manual’ or ‘Automatic’.
If it is set to Manual, then you will notice an editable 'Processed' tick box field is available.
However, if program line processing is set to Automatic, this field will be read-only and set automatically when payment lines are edited or receipts are allocated in the Finance app.
Once a program line has been marked as processed, it will no longer be possible to edit or delete the program line, even if the receipts have been unallocated/removed. Please raise a ticket if you need to edit or delete a program line that has been marked as processed.