I let it sit for a few hours and was able to directly access the setup page again. Went through the initial setup, got into the app, restored a configuration backup, and now its unusable again.

I'm really starting to think its just impossible to work with this Omada software if your network range is anything but the expect 192.168.0.0/24. I use 10.0.0.0/24 and have had nothing but problem after problem with this OC200 because of it. 

@Somnus I've got a ticket in, just waiting and trying to figure it out on my own in the meantime. 

Probably just going to have to go back to a software controller until I can get rid of this whole stack. Trying to do this "centrally managed" thing has really cost more time than it has saved.

@Fae My OC200 will never come up in recovery mode.

I disable my security software

Plug my PC directly into Eth2

Configure my IP settings as specified

Press and hold the reset button, then plug up the power.

The Cloud light flashes once, is off for a second, then flashes repeatedly for a few seconds until it stops.

I then let go of the reset button.

I am never able to reach 192.168.0.253. I have redone all these steps 4 times, have tried 4 different browsers, and have also tried to ping 192.168.0.253. There is never any response.

And apparently because I mentioned a "thunderstorm" the TP-Link support team refuses to even try to help me with my issue.

Nevermind the fact that the device was on a PoE Switch with 7 other devices, none of which are having issues. That the PoE switch and everything connected to it was plugged into UPS battery backups. No, you said "thunderstorm" so warranty invalidated!

I can not believe this.

And on top of that, I can't switch back to a software controller without going and pulling stuff off of walls to reset it because the omada controller sets a name and password that isn't the login name/password on the devices, making it impossible for me to adopt them to a new controller instance!?

Tried again to go through the whole process. Can never get it to go into "Recovery Mode". I was able to once again get to a normal "first time setup" page, went through that entire process again, flashed new firmware via the Maintenance tab, restored my latest auto-backup, and it stopped responding again. Won't show up on Eth2 or Eth1 with the fixed 192.168.0.253 IP, and won't pick up an IP Address correctly via DHCP on my normal network that it used to manage itself.

I'm guessing there is something wrong with my auto-backup, though I can load it into a Software Controller and it doesn't have any issues.

This has just been a big stupid mess.

I have given up on ever getting the OC200 working again, so I decided to switch back to a software controller for now.

Got it running, loaded a backup, every device is "Managed by others".

Okay, so I have to go around and reset every device in the house?

Did that, adopted the Gateway, none of its configuration exists? Even though I restored a backup? I guess because you can't configure some thing "without a gateway attached".

Okay, let me restore a backup again.

Oh nice, now the Gateway is "Managed by Others" again, but it's automatically taking over my WAPs? I guess because they are reset?

So there is actually no way for me to ever restore Gateway configuration from a backup?

Very nice.

At least working with a software controller it's much easier to deal with the "Adoption Failed" continuous cycle of adopting a Gateway with a different subnet.... good old ipconfig /release and ipconfig /renew.

If you have a backup or way to access the old controller. The device password the controller uses is under Settings > Site> Device Account
(Maybe need to tick advanced to show?)

If you set the same Device Account username/password on the new controller, it should be able to take over.