Symptom

You create an invoice, but the payment part with the QR code is missing. Typically, it appears like this:

• In the invoice draft, the QR tab is present, but the page remains blank (0 pages).
• The generated PDF does not contain a QR payment slip.
• The QR payment slip is instead printed directly on a paper printer.
• In newer versions, the message appears: "The printer driver 'Microsoft Print to PDF' is missing on your Windows system. Please install the driver to be able to print PDF documents!"

The problem affects Windows workstations exclusively. Macs are not affected.

The following two checks fix the cause so that the payment part appears automatically in the invoice again.

Cause

Windows does not generate PDF documents by itself. For this, there is the virtual printer "Microsoft Print to PDF": It belongs to Windows, looks like a normal printer, but does not output paper; instead, it writes the printed content to a PDF file.

This exact method is used by timeSensor LEGAL to generate the QR payment slip: The QR page is sent to "Microsoft Print to PDF", returned as a PDF, and attached to the invoice. Therefore, it is not enough that the printer exists on the PC – it must also actually be selected for the QR page.

This selection is local on your workstation. Various events can make it unusable without you noticing:

• a Windows update or newly installed printer software
• a computer that was abruptly shut down, e.g. due to a crash or power failure
• a changed default printer
• a workstation you took over from a colleague

Afterwards, the saved setting points to nowhere: timeSensor no longer finds the printer or uses another. Depending on the situation, the QR page then remains blank – without any error message – or the payment part ends up on the last used paper printer. Both look to you as if the QR code is simply missing.

The invoice data itself is not affected: the QR code is correctly calculated, only its output fails.

Check 1: Is the printer present on Windows?

1. Open Settings... → Bluetooth and devices → Printers and scanners.
2. Search the list for the entry Microsoft Print to PDF.

If the entry is present, proceed to Check 2.

If the entry is missing, activate it:

1. Press Windows key + R, enter optionalfeatures optionalfeatures and confirm with OK.
2. In the window, Windows Features check the box for Microsoft Print to PDF.
3. Confirm with OK and restart the computer.
   

Check 2: Does timeSensor use the correct printer?

The printer may exist but still not be used – for example, if a paper printer is assigned for the QR page. This is the case when the payment part is printed on paper.

Print settings are saved per tab, so separately for the QR page:

1. Open the invoice so that the draft with the tabs is visible. Click below on Print.

2. Select the printer "Microsoft Print to PDF" again and close the window.
3. Log out of timeSensor and log back in.
   

How to check if it works

Create a test invoice. In the QR tab, the payment slip must be visible, and the generated PDF must contain the payment part.

If the QR code is still not visible, reload the resources – instructions are in this article.

If it still doesn't work

Until then, you can continue working immediately and do not have to wait until the cause is fixed: You can generate the payment slip anytime as a single PDF under the QR tab via Printing... and attach it to the invoice.