| Error Message | Solution | |---------------|----------| | “Error: Wrong file. Please check the hardware version.” | You downloaded firmware for V3 or V5. Redownload the V4 file. | | “Upgrade failed – header mismatch” | Unplug all Ethernet cables except your PC. Disable antivirus temporarily. | | Router stuck on blinking power LED after upgrade | Perform a : Hold reset button for 30 seconds (powered on), keep holding while unplugging 30 sec, keep holding while plugging back in 30 sec. | | “No internet after upgrade” | Log in and go to Network > MAC Clone . Clone your PC’s MAC address. Reboot your modem. |

Real risks of running old firmware: