I just want to add .. I had difficulties in uploading the latest firmware.
The first issue I had was that I tried to upgrade using Bluetooth. Firmware upgrades are not done over a wireless connection because if they fail the result can be damaging to the device.
YET the manual does not explicitly say you cannot upgrade firmware over Bluetooth.
Second issue I had was that when connecting via USB I had 4 x COM ports on my Windows 10 PC. No matter what port I selected it was telling me it was connected. mBlock needs to know if it is connected to a known, supported, device. (Not sure why a device like this can't just support native USB and not serial to USB)
Thirdly the default board was set as mBot(mCore) I just assumed this was correct but I have the mBot Ranger so I had to select mBot Ranger (Auriga) board.
The reason I mention the third issue is because of all of the forum searches, about firmware upgrade issues, this was never raised.