There is an extension conflict between the CoStar printing extension and Desktop Printing.
Workaround
Change the load order of extensions making the Desktop Printer Menu load AFTER the CoStar printing extension. Since the CoStar printing extension comes with a "¥" before it, you can also put the "¥" before the Desktop Printer Menu extension so that it will load after the CoStar extension (since it is alphabetically after "CoStar").