The firmware is a legacy build for Ubiquiti airMAX M-series devices. Because this version is over a decade old, it is primarily used for recovery or maintaining compatibility with specific older hardware revisions. Download and Official Sources
Would you like help determining if your device is XW (vs XM vs XC), or need the direct v5.5.6 download URL (if still live on Ubiquiti’s CDN)? Ubnt Firmware Xw.v5.5.6 Download
Firmware version 5.5.6 is extremely old (circa 2013). It contains known security vulnerabilities and lacks modern encryption standards (WPA3, AES-256). The firmware is a legacy build for Ubiquiti
: If you are trying to downgrade from a newer version (like v5.6.x or v6.x), be aware that changes in the U-Boot bootloader in newer firmware may make downgrading difficult or risk bricking the device. How to Install Firmware version 5