Please contact us on firstname.lastname@example.org
or call +44 (0)1284 725 725 (9am-5pm GMT, Monday-Friday) and we will be happy to reset the system to allow you to print again without having to purchase a second time. If you have a problem outside of our office hours and you need your music urgently, please purchase again and send us an email to explain what happened and we will cancel the initial order, so you don't get charged twice, as soon as we get back into the office.
Then, when you go to print the score again, in the print dialogue window that pops up, change the 'Substitute Lines' setting (on Mac this is in the Sibelius area of the dialogue window): if the box is already ticked, untick it; if it's empty, tick it. Then click OK.
If the problem persists, please contact us again and we will look into it further for you.