The IllegalOperatorSequence error you are receiving is coming from your printer and not from Musicroom or the Scorch file you are attempting to print. You may wish to check if you have the latest available driver for your printer.
You should be able to download the latest driver from the printer manufacturer's web site:
After downloading the driver, follow the instructions on the manufacturer’s website to install it.
Please contact firstname.lastname@example.org
or call +44 (0)1284 725 725 (9am-5pm GMT Mon-Fri) if you require further assistance or if you need us to reset the system to allow you to try printing again.