Txnr646 Firmware Update 2021 [verified]

This indicates a network transmission failure during the download. Switch from Wi-Fi to a physical Ethernet cable.

Note: The specific model is the Onkyo TX-NR646 (a 7.2-channel network AV receiver released around 2015/2016). By 2021, this device was considered a legacy product, but Onkyo released critical stability and security patches for it. txnr646 firmware update 2021