If the LED is flashing in red or an error message is displayed on the computer, check the following:

Is tape stuck inside the machine?
If you found a label stuck inside the machine, remove it carefully so as not to damage the printer.

Is the Gap/Black Mark Sensor calibrated?
For details about how to calibrate, see the step of using the BPM in the FAQ: "How to load the Media".

Is the paper size set properly?
Check that the paper size is set to the same as the roll installed in the printer as follows:

1. Connect your computer and the printer, and then make sure that the printer is turned on.
2. Start the BPM, and then click the Printer Configuration button.
3. Check the Paper Width / Paper Height settings in the FBPL tab.