Why am I not able to process Unprocessed bookings in Owner Statements?

Print The reason it's showing unprocessed bookings because you haven't processed the statement for the previous month, it must be still open somewhere. If you want to process them, you have to open the statement for the current month(where it was processed) first and then you will be able to see the statement for the old months to verify the previous bookings and then process them first.