Just preserving some notes for anyone doing an install in 2026.
UniFi FW was v6.6.71 (just from SSH login, didn't check deeper). There were some notes on wiki page and a few threads about only the older firmwares working, but mine went smoothly today. Dunno if mine was stuck in a warehouse though, cause there are way newer fw's on their site.
Steps 3, 5, and 8 (bootloader steps) don't echo back any confirmation, so don't worry.
Step 6 (scp transfer) isn't really detailed, but you're basically transferring the bin over, so that the subsequent commands unzip it locally on the 6+. I renamed my download to the shortened "openwrt.bin", then ran scp in a separate Konsole so I didn't mess up my SSH connection. If you also get the "sftp-server" error, apparently it's cause the 6+ needs the legacy scp support or something, so use "scp -O" instead (capital o, not a zero).
Other than that, following the instructions went perfectly. At this time, wiki says only 24.10.5 is supported, so I just went with that (only 6mo old). Not quite sure if that's just waiting for a community member to be the guinea pig, or if there's some deeper validation process on here.
Good to hear the install procedure still works. As far as I know, there has been no confirmed reports of the procedure not working on newer stock firmware versions ever since I wrote the initial patch adding UniFi 6+ support. Note that I wrote on the wiki page:
This procedure has been tested on stock UniFi firmware up to version 6.6.55, but likely also works on later versions.
Most common problem is someone contravening the instructions and attaching the AP to their network and not their PC during the initial setup.
That is correct, and it's because recent versions of OpenSSH's scp command actually uses SFTP which isn't supported by most stock firmware. It's a fairly common installation issue and really needs a dedicated wiki page explaining it.
Wiki pages are not automatically synced to the latest built version. Use the Firmware Selector to check for the latest version. For example, here's 25.12.4 for U6+.