@Hank21 The 3 OC200 V1's are 5.12.9 for the firmware.

I'm assuming I should be where they are to do the forget/re-adopt, incase something really goes south.

I tried doing a ping test at one location, the switch could see both.  I can also VPN in on both and see both, the one ER7206 has the OC200 directly plugged into it, the other has a switch in the way, but neither are affected by any communication issues.

Seems 2 out of the 3 either failed to upgrade to 1.4 or did and somehow the communication part isn't working.  I did use the controllers at each and backup the settings (for safety sake).

What to do *IF* the adopt doesn't work?  Factory and try it again?  If still no adopt after that then, re-upload manually and repeat the adopt?

Is there any online steps when this happens after an update?

  @Clive_A There are 3 locations, 3 OC200s talking to 1 ER7206 each (the controllers are at each location, one plugged directly into the ER7206).  2 failed to update (I think) and are not responding and showing Disconnected, one worked properly.

Is forgetting and re-adopting going to cause any issues with settings?  Will I need to factory reset the ER7206 just to re-adopt after a failed? firmware upgrade?  I have no idea the state of the device.  If the login page had listed what version it was running (even at the point of not allowing any further action from it being controlled by the OC200), it would have at least given information as to how far the upgrade went.

  @Clive_A 

What I did was this:

Omada Cloud (tplinkcloud.com)

In that list I saw 3 controllers listing an UPGRADE.  I clicked on each and told the ER7206 on each to Upgrade, it listed it was upgrading and I went to the next one.

Each OC200 runs 1 location's AP (3 locations have ER7206 and 1 location has 2 switches).

2 of the 3 ER7206 upgrades showed Disconnected afterwards.

Today, I "forgot" the one Disconnected unit, power cycled it and now it wants a factory reset to start fresh (but I can't because I got a stampeed of feet asking where the internet went).  My concern is having to re-setup the ER7206 again in both locations, but if I restore the settings in the OC200, it (in theory) should restore the settings to the 7206 that was freshly adopted (if it has none to add to it).  I am unclear the data storage for the OC200 and whether or not forgotten devices have their settings/data removed.

All of the OC200s sit on battery backups solely for the OC200 and the APs that they control, only 3 locations have ER7206 routers and they're also on backup with the OC200 and there is another device on each location that offers the battery status reporting.

The devices aren't in locations where regular people can touch them, the one today I needed a ladder to get to, plus the update was done at midnight when nobody is there.  One location I checked the security cameras to ensure it was safe, but I know nobody can get in there, I'm the only person with the key.  The only one that didn't fail, is actually the easiest to get to (figures).

I've scheduled a time next week to come in and factory reset the ER7206 that is asking for it to be done before it can be re-adopted.  This isn't until after Christmas, so when I factory reset it, I'll log in to see what version IS in the unit (since that is the only means of doing so, can this be added to the title page to list the build version in future releases), if it isn't 1.4 which it should be, I'll manually upgrade it then.  I'll only know after that is done, what will happen next.

Okay, the 2 sites have been visited:

1 went alright, the other one, not.

The suggestion to "Forget", "factory reset" and "Adopt" was the worst of the two:

1. The unit was Forgotten, kept working.
2. Today - Factory Reset (using the login and pushing the Factory Reset web button).
3. Surfed in to 192.168.0.1 and put in new credentials.
4. Signed in and proceeded to upgrade the non-upgraded 1.3 to 1.4 using a manual upgrade.
5. Once rebooted, signed in, changed IP address to 192.168.1.1.
6. Signed back in at the proper router address for the location and proceeded to enable Cloud management.
7. Waited 10 minutes, unit said "Online".
8. Used Tools on both OC200 AND the ER7206 to ping each other, they could.
9. Waited another 10 minutes, gave up and started manually reconfiguring the ER7206 without the OC200, as the OC200 still can't see it.
10. As of current, the OC200 cannot see the ER7206 and there is no network interference between the two devices.

The unit I was suggested to "pull the plug and plug it back in" was the best of the two:

1. The ER7206 took over 3 minutes to show up after a power cycling, presume it was doing cleanup, normally boots take a bit over a minute.
2. OC200 found the ER7206 and did the usual Provisioning ... Configuring ... Connected.
3. OC200 checked for updates (by request), none found, unit still at 1.3.  Manually updated to 1.4 using download via the OC200.
4. ER7206 upgraded, restarted, communicated with OC200 and after the usual song and dance between the OC200 and devices, it was Connected.
5. The unit is functioning properly again after failing to upgrade.

So I've manually edited the ER7206 configuration at the one site that the OC200 can no longer see the ER7206.  My only thought is, the hardware will either have to be replaced or the OC200 totally factory reset to get the ER7206 back, as the OC200 simply doesn't see the ER7206, even with the Controller IP address being added to the ER7206's configuration.

In Summary:

2 of the 3 ER7206's upgrading from 1.3 to 1.4 failed somewhere in the upgrade and apparently never rebooted.  The "Forget" and "Adopt" method here is BAD as a suggestion.

So now where do I go from here?