Lexmark T644 Laser Printer "flushing buffers mean" Questions

been printing chapters in a book. One chapter will not print. The message on the Lexmark screen is "flushing buffer". does anyone know what this means or why it will not print? We have Lexmark Optra S

...on by pressing blue arrow button Hi, The problem could be several things, the first one could be a Flushing buffer error. That means that the printer did not understand the print job sent to it and ...