| Error Message | Solution | | :--- | :--- | | Invalid firmware image | Your device is XW/AC chipset. Version 1.255 is incompatible. | | TFTP timeout (0x0) | Firewall blocking TFTP (UDP port 69). Disable Windows Defender temporarily. | | Upgrade stuck at 50% | Bad Ethernet cable. Use a known good Cat5e cable under 10ft. | | Bootloop after upgrade | Corrupt NVRAM. Perform a 30-30-30 reset: Hold reset button for 30 seconds, unplug for 30 seconds while holding, plug back in while holding for 30 seconds. |
The term (a common shorthand for Ubiquiti) and Upgrade Firmware strongly suggest this relates to updating a PtMP (Point-to-Multi-Point) base station —specifically, an airMAX sector antenna managing up to 255 client stations. --- Upgrade Firmware Version 1-255 Ubnt Download