Double-check to see that the printer has enough paper - if your reel is out, you can simply swap it out, and the printer will continue to print.
Internet access is often required for printing to work effectively since your transaction information is fetched from a server. Be sure to double-check that your internet connection is working.
If neither of the above are the issue, we're always here to help. Feel free to get in touch with us and we'll get you back up and running, day or night.