If the printed invoice lacks the Microsoft Yahei font, you can use the following solutions:

1. Download and install the Microsoft Yahei font: Download the Microsoft Yahei font from the Microsoft official website and add it Install it into your computer. Once installed, your computer will have this font that can be used when printing invoices.

2. Export to PDF file: If the problem still cannot be solved, you can export the invoice to a PDF file. Fonts in PDF files are usually embedded in the file, so there will be no problem of missing fonts when printing. Use PDF editing software such as Adobe Acrobat to convert the invoice to a PDF file, and then print the file.

3. Consult the printer manufacturer: If the printer cannot print Microsoft YaHei fonts, you can contact the printer manufacturer for help. They will provide solutions such as updating printer drivers or changing printer settings.