I started out with ~20 devices and that seemed to be stable, but im up to ~35 now and even with a reset / powercycle every day, it barely works. In the developer tools website, it shows most devices with an X in the Online column.
Im connecting them directly to Homey, not via the Ikea gateway.
It this supposed to work? would reconfiguring them all to use a ikea gateway solve any problems? create new ones?
Any help would be appreciated!
Remco
Hm im now getting āError: manager.zigbee.controller_start_failed Try restating Homeyā, but ive tried that a few times and the issue remains.
Pull the plug from Homey for about 11 minutes. Then power it up and wait at least 20 minutes for it to startup. Then check if the devices are all loaded again (no spinners in their icons). And then check if the error is still there.
Report that error to Athom please.
I donāt want to be a partyp**per, but it sounds like you need to perform a zigbee reset if you havenāt recently.
You have to pair all zigbee devices again, and repair all flows with these devices in them.
Make sure to fix your wifi channel (preferrably to ch. 1, 6 or 11)
When zigbee resets, it picks a quiet ch. so the least interference with your wifi will occur.
When pairing devices again, make sure you first pair the smartplugs and lightbulbs.
After that, pair your sensors and switches close to the smartplug or light wich is closest in range when mounted.
Zigbee
Interference check:
http://ostgardh.se/wifi_zigbee/index.html
Explanation:
Which wifi channel:
http://wifimetrix.com/channels-1-6-11-only
Athom advice:
Testimonial of a user, after his zigbee was reset:
I have tried the 11 minutes off - on - wait 20 minutes a few times, but no luck. still same error starting Zigbee. For the zigbee reset (and other purposes): how awesome would it be to have a āreplace deviceā function? select a new device, select the old one, and it deletes the old one and replaces it with the new one? in all flows, scripts, copying name, room etc, everythingā¦ we can dream!
I have made a support case with Athom, and i hope they reply quickly, there are only very few lights in my house working at the moment 
We all know it is not what you want. Itās great you contacted support about this.
The design of zigbee is this way. Reset = start all over.
I think this kind of issues never was expected, so no "if old device-id = A, then new device_id = A functionality.
Spend a day to repair all things, thatās the quickest solution for now.
No consolation now, but using the groups app can often save some time when you have to replace devices. In cases where you have several flows that control one or more devices you can add the device(s) to a group and then control that group from the flows. That way you only have to update the group if you have to replace a device.
The design of Homey is this way. It isnāt limited to Zigbee either: when a device is paired with Homey is gets an internal unique identifier, and this identifier is used to reference the device from flows, scripts, etc. If you need to re-pair the device for whatever reason, it gets a new identifier, and flows/scripts need to be fixed.
I donāt know why Athom chose to implement it this way. An app that implements device support needs to provide unique ādataā to identify a device. A developer can choose this identifier themselves, and itās typically based on something like a MAC-address, serial number or IP-address. If Athom would base the internal identifier on this information, it would be possible to re-pair the device without breaking references.
but im sure you can make a function that loops through all flows (as a start) and replaces the old UUID with the new one?
Iāve never tried myself, it might be possible. If so, I wonder why Athom never considered offering such functionality from an easy interface.
Correct, but I didnāt feel like to explain it to the exact story the other day. I just wanted to point out he can mail support what he wants, but the quickest fix is to start over, and for now there are almost no other options.
But youāre absolutely right Robert.
I just think the devops/sales/board of Athom never expected something could break down or needs repair 
That sounds like a very real scenario, and āseemsā not very complicated to implement by Athom. Maybe in the summer of '69! (2069).
I contacted Athom support and i got a magic reset procedure that did the trick, for about a week, did it again, another week, and many reboots later, i gave up. I got a ā¬30 ConBee II USB stick ( ConBee II Overview ) , installed their docker container on a my synology NAS and installed the deCONZ app in homey. zigbee was never this responsive! even the dimup/dimdown feature works in Ikea remotes
So, the problem with manager.zigbee.controller_start_failed was never really solved? Did you reply to Athom support to tell them that its still a problem?
Im wondering because I got the same issue today, on my new Homey that I bought a couple of weeks ago. I sent a support request to them and awaiting their response.
The magic reboot sequence did solve it, for a few days, may be a week. How many devices do you have paired? It looks to me like if you have more then 10 - 20 devices, you might want to look at alternatives like i posted above. that setup is still working like a charm!
I also think it has something to do with the amount of devices paired. Seems to be failing in a larger network somehow.
Walked the same pathā¦ Same errorsā¦ Same results! Today I re-installed my Ikea hub and started using the Ikea gateway app instead of linking all devices to Homey. Now all thatās left is some temperature and lux sensors and some smart buttons. Hopefully this keeps stable!
