To upgrade your Ubiquiti (UBNT) firmware safely and for free, you should download official files directly from the manufacturer. Websites promoting "Free Downloads" for arbitrary version numbers like "1.255" are often third-party mirrors or phishing risks that may contain modified, unsafe files.
The pursuit of a FREE download of Firmware Version 1.255 led Alex through various forums and community discussions. Many users had similar needs and were sharing links and advice on how to obtain the firmware. However, caution was necessary; downloading from unverified sources could pose significant security risks. A few threads mentioned a now-defunct repository that had hosted older firmware versions, including 1.255. The link provided was dead, but it sparked an idea. Upgrade Firmware Version 1.255 Ubnt -FREE- Download
Here is the most critical part of the article. Many third-party websites claim to offer "UBNT Firmware 1.255", but they often bundle malware, spyware, or corrupted images that can brick your device. only To upgrade your Ubiquiti (UBNT) firmware safely