As for your firmware update issue, just to be absolutely clear, the update file has to be named exactly as per the instructions - including the capital/lower case letters. This is linux, so these things matter.
Assuming the above to be okay, you could always try formatting the USB stick using the specific utility detailed in "Documentation", "FAQs", "Formatting USB Sticks" in the Web Interface documentation. I've never had to do this but it's in the FAQs because many people had success with it. Worth a try.
Assuming the above to be okay, you could always try formatting the USB stick using the specific utility detailed in "Documentation", "FAQs", "Formatting USB Sticks" in the Web Interface documentation. I've never had to do this but it's in the FAQs because many people had success with it. Worth a try.