Unfortunately, the MM731 CANNOT update the FW in Wired mode. When open the MasterPlus+ software, it will automatically read the current FW version of the MM731 and pop out the upgrade instructions.
Please do not close the MaseterPlus+ and follow the instructions show on windows to update the firmware again.
Toggle the bottom switch to 2.4 GHz mode.
Unplug the USB cable
Plug the Dongle into your PC and make sure the MM731 is connected in 2.4 GHz mode.
When the firmware update window pops out, click “OK” or press Enter key to start the update. Please make sure to follow the instructions through the whole updating process.
After both the mouse and dongle firmware are updated, you can confirm the firmware version has been updated. Now the MM731 firmware update is fully completed and your MM731 is ready for normal use.