Hub Model C8 - Platform version - 2.3.8.134
I go to bed and everything is working. I wake up and everything Hue or Kasa is working and nothing else is. Presumably Z-wave is down. I have many switches and plugs all z-wave.
I've started a z-wave repair and it's been going for at least 45 mins and is just spinning on Stage: Mapping Network - Refreshing Node States
I feel like this should not happen. Nothing changed. I will try the troubleshooting tips here.
Hubirat 
Following the steps is a good idea!
You may only need to:
Out of curiosity, are you seeing a (1) in a red circle 
on the top right of the hubitat screen? If so, click on it to see the message. I would not be surprised if you saw a message reporting a backup failure at the Z-Wave step. If so, this is a known issue that is being actively worked on.
"Have you tried turning it off and on again?" Classic. 
And yes, I did have the indicating a failed z-wave backup. I am currently restoring from the last successful cloud backup. 
Any ETA on the fix?
Restore did not fix the problem. I'll try the Shutdown | Unplug | Wait | Plug-in version.
It's not a silly as it seems.
If you shutdown the hub. The z-wave radio remains powered and if it's corrupt, will remain corrupt.
If you power down the hub, the z-wave radio powers down and on power up, MAY, clear out any corruption that might exist.
Oh absolutely, 
agree! But it really is classic. It's an actual a meme!
But yes, it also works.
Literally it worked. I'm back up. Z-wave devices are functioning as expected.
That was unnecessary. Radio backups are only needed to restore on a new hub in case of total hub failure. Otherwise it will not help anything.
The fix is to power it off and unplug for 30 seconds to restart the radio, as instructed.
If it is a reoccurring problem then staff will certainly want to look into it further.
Download the Hubitat app
