Rich's Tongfamily (Richtong.net add-on)

Well, sometimes things don’t work. I’ve been telling everyone to get an Unifi instead of consumer grade hardware, but today I got caught. If you have the “square” access points, they are effectively dead. These are called Unifi UAP AC and they use the Broadcom chipset that has been buggy and is now unsupported.
Super sad for folks who thought they would support old stuff, it turns out the “round” ones still work even ones that are older than the square one. So you are warned.
If you have this problem, you have two horrible choices. Stick with Unifi Controller 5.6 and miss the bug fixes or replace those Unifi UAP AP. A little depressing.
The main solution is that you have to run two totally different Unifi controllers. One for the obsolete ones the UAP AC and one for the new ones.
It is actually quite easy right now to do this with home brew. On one machine run
brew cask install Ubiquiti-unifi-controller-lts
This will install version 5.6, the last version that supports all Unifi access points. Then connect all your UAP AC’s to it. The easiest way is to run a backup of the configuration files and then restore into this machine and then delete all the APs but the UAP AC’s
Then on another machine, run
brew cask install ubiquiti-unifi-controller
This will install the latest Unifi controller, currently version 5.8 and connect all other devices to it. Run the same backup and then delete the wrong ones trick to make it all work.