If you are experiencing issues with the DYMO XTL 300 machine not recognizing tapes, it may be that your machine needs a firmware update.

The first thing that DYMO recommend when your XTL 300 machine doesn't recognize the tape cartridges is to update the firmware. Below you is a step by step guide on how to do it from DYMO:

Update the XTL 300 firmware through DYMO ID:

1. Connect the printer to your computer.
A message screen should appear stating that a software update is available.
2. Follow the instructions in the update screen to update the software.

If the software update screen does not appear after connecting the label maker:

1. From the DYMO ID menu, select About > Label makers and select your label maker.
2. Select Update available.
3. When the update screen appears, follow the instructions to update the label maker software.
4. When update is complete, turn the power off and then on again.

Press and hold the power button for at least five seconds to make sure the power is completely off and not just in standby mode.

We hope this is of help to you!