If you're unable to find the specific firmware version 1.255 for your Ubiquiti device, it's possible that it may not be publicly available or compatible with your hardware. Always refer to the official Ubiquiti support or forums for guidance specific to your device and situation.
Before starting, it is highly recommended to and support info files to prevent data loss in case of a failure. 1. Locate and Download the Firmware upgrade firmware version 1.255 ubnt download