2.3.2.3.1 Troubleshooting

If there are any issues during the FW upgrade process, check the following points:

• Note that the upgrade process will fail if DebugWire is enabled on the megaAVR. Make sure the DW fuse is un-programmed, and that the ISP fuse is programmed.
• The mEDBG Virtual COM Port must not be opened in any terminal programs, such as PuTTY or TeraTerm
• Make sure that the mEDBG Virtual COM Port driver is installed and shows up in the device manager. If it is not shown, download the drivers via the Extension Manager in Atmel Studio: Tools → Extension Manager and search for the Atmel USB Installer.