I don't understand what unified AP code and "ONLY ON DEFAULT CONFIGURATION" means.
These are Instant APs. They were factory reset via the boot method and booted into Instant mode fine per the previous instructions - (e.g: connect to Instant SSID, browse to GUI, login with admin/admin, configure).
After upgrading the firmware and rebooting, the Instant SSID is no longer there - the user guide indicates this has been replaced with a SSID of SetMeUpxx:xx:xx.
Per the new instructions:
Manual Conversion of AP to Instant AP
If the AP cannot be upgraded into an IAP through a virtual controller, Activate, AirWave, or Central,
users can connect to a special provisioning SSID broadcasted by the unprovisioned AP to manually
convert the AP to an IAP through the WebUI. To manually convert an AP to an IAP in the WebUI
1. Login to your virtual controller.
2. Connect to the following provisioning SSID broadcasted by the unprovisioned AP: SetMeUpxx:xx:xx.
3. Open a web browser. You will automatically be redirected to a special provisioning page in the
WebUI to convert the AP.
4. Under Access Point Setup, select Image File or Image URL to upload the Instant image.
If you select Image File, click Browse to locate and select an Instant image file from your local
file explorer.
If you select Image URL, enter the web address of the Instant image under URL.
5. Click Save.
After the AP is upgraded, it reboots in Instant mode.
I've followed these instructions and https://setmeup.arubanetworks.com:4343 does not load. Trying to enter 172.31.98.1 ends up resolving to the above URL and does not load.
Since the PC is connected to the SSID being broadcast by the Instant AP, and not any other network, any other network DNS would not have anything to do with browsing to the GUI.