This means the receipt printer was not set up correctly in ProDOC.  Follow these steps to resolve this issue:

  1. Double click on the ProDOC icon by the system clock to open the "Setup" window
  2. First, ensure the "Used stored settings" box underneath the "Receipts Printer" line is checked
  3. Click on the "..." button to the far right of the "Receipts Printer" line
  4. In the drop down, ensure your thermal printer is selected
  5. On the bottom left of the printer setup window, ensure the size is "Roll Paper 80x297mm" and that the source is either "Document(Feed Cut)" or "Form(Partial Cut)"
  6. Click OK out of all setup screens
  7. Reprint a receipt to test