Note: Ubiquiti now uses ui.com. If the above returns 404, use the archive path:
For wireless links (PtP and PtMP):
A: Re-download the UPD file. Use a different browser or disable antivirus temporarily. The file size must match exactly the official release notes value (e.g., 8,192 KB). Upgrade Firmware Version 1.255 Ubnt Download UPD
A: Yes, but not always directly. Ubiquiti includes a squashfs filesystem that may prevent downgrading across major kernel changes. Use the TFTP method and an older UPD file, but be aware that downgrading can cause factory default loss.
If issues occur (boot loop, radio failure): Note: Ubiquiti now uses ui
Verify your device model before proceeding:
| Product Series | Compatible Models | Firmware File Type |
|----------------|-------------------|--------------------|
| AirMax M | NanoStation M2/M5, NanoBridge M, Rocket M, Bullet M, PowerBeam M | .UPD |
| AirMax M Titanium | Same as above | .UPD |
| EdgeMax (Legacy) | EdgeRouter Lite, EdgeRouter POE (v1.x firmware path) | .tar or .UPD | Verify your device model before proceeding: | Product
Important: Do not use v1.255 on AirMax AC, UniFi APs, or EdgeMax X/ER-4 series.