This problem may occur on some Windows computers.

To resolve the issue, make sure you are using a COM port compatible with your printer.

To change the printer port, follow the steps below:

1. Open the [Devices and Printers] window. (Refer to the FAQ: “How to open the Devices and Printers window“.)
2. Right-click on the model name of your printer and select [Properties].
3. Open the [Services] tab and confirm the COM port specified for the Serial Port Profile (SPP) option, and then click [OK] to close the window.
4. In the [Devices and Printers] window, right-click your printer and select [Printer Properties].
5. Open the [Ports] tab and select the same port as you confirmed in step 3.
6. Click [OK] to close the window.