Go to web.archive.org and paste: http://dl.ubnt.com/firmwares/XM/v1.255/ You may find snapshots from 2014–2016 with downloadable bins.
Since this firmware is ancient, you must take extra precautions: --- Upgrade Firmware Version 1-255 Ubnt Download
: This malware primarily infected Ubiquiti devices running older versions of Go to web
Before diving into the upgrade process, let's quickly discuss the importance of firmware updates: --- Upgrade Firmware Version 1-255 Ubnt Download
: Unofficial downloads may contain malicious code or backdoors.
Improved high memory usage reporting and added unstable process detection.