If the update fails or the receiver behaves strangely afterwards, you may need to restore the firmware.
Release the buttons once the display begins flashing at intervals of about 1 second. Denon Avr E300 Firmware Update
: If an update is found, select Update Now . The display will show the estimated time (usually 10–30 minutes). Method 2: Manual Update via USB If the update fails or the receiver behaves
Typically 20 to 60 minutes depending on server speed and network traffic. Denon Avr E300 Firmware Update
Release the buttons once the display starts flashing at intervals of about 1 second.