After turning on your USG Pro 4 for the first time, you navigate into it's default LAN ip address https://192.168.1.1, and under "Setup my Unifi Gateway" you clicked on "set inform URL" then added the address http://[your server]:8080/inform and then clicked OK.
You looked into your controller server and your new USG Pro 4 is not showing up on your devices to be adpoted so you go back and refresh your USG Pro configuration site https://192.168.1.1 to realize your settings didn't take.
This is a bug that as of today, even the most updated version 184.108.40.20643895 of USG Pro has not fixed yet.
Solution is quite simple, DO NOT waste your time trying to upgrade/downgrade java or your controller. You will find plenty of forums advising that. Here is the real solution:
1. Install Putty (get it quickly from https://ninite.com/putty
2. Open Putty and establish an SSH connection to your USG at https://192.168.1.1 (default user/password is ubnt/ubnt)
3. At the command line, type: set-inform http://[your server]:8080/inform and then hit enter
4. Go to your Controller and Adopt the device, then wait until the adoption process is finished. You will see the device does not come back online after adoption because the bug makes it loose the inform url again even after the adoption process, therefore, continue the guide as follows:
5. Verify the device is back up by navigating to https://192.168.1.1
6. Go back to your Putty Session and run the same command again: set-inform http://[your server]:8080/inform
7. Check on your controller to see if the device comes back online.
We hope this bug gets fixed in future firmware releases, but in the meantime, keep this guide saved to your bookmarks, you will need it each time your power-cycle your USG.
Please leave your comments, let us know how this guide is working for you but most importantly call us if you need assistance or support with other networking needs.
Deploy dozens of computers in minutes with iEple's BioGreenPC
Enterprise I.T. Support for ALL