Step 1

SSH in to the Unifi Access Point using the default ubnt / ubnt password

Hint: if the AP isn’t brand new and you’re trying to fix it via SSH you will need to find the username and the password from the old controller. As of writing this is located at System Settings > Controller Configuration > Device SSH Authentication.  Once you log in you’re going to want to type in set-default to factory reset it first.

Step 2

Upgrade the firmware first by typing in

upgrade https://dl.ui.com/unifi/firmware/U7PG2/4.3.28.11361/BZ.qca956x.v4.3.28.11361.210128.2309.bin

Where https://dl.ui.com/unifi/firmware/U7PG2/4.3.28.11361/BZ.qca956x.v4.3.28.11361.210128.2309.bin is the current firmware available at Unifi Downloads

Step 3

Connect back to the Unifi Access Point using the default ubnt / ubnt password

Set the inform address as

set-inform http://thecontrollerlocation.com.au:8080/inform