I've had an ongoing issue upgrading the platform on my C7 to 2.3.9.2XX. The long and short of it is that the hub would get stuck at "25% updating device drivers" and then cycle back to a reboot. The only way I could get it back working was a downgrade to 2.3.7.146.
Well...today, I finally fixed it! Not sure what is going on, but this is what I discovered.
The database, somehow, was causing an issue. I hesitate to say "corrupted" because it worked in 2.3.7.146. I had 2 devices (Z-Wave) that I only use around Christmas to control lights, so they are off the network most of the time. I also had a switch, that I'm in process of moving around the house, so it, too, was in the database, but not actually in the network. I removed the uninstalled switch, and plugged in both of the other two devices, so that I didn't have any more ghost devices. Then I went through all my custom code and deleted drivers and apps I'm not using, and updated drivers that I could from posts.
After that, I did a platform upgrade from 2.3.7.146 to 2.3.9.201. It did do a couple of restarts, but eventually it got all the way through and is up and running.
I've been operating with ghost devices for a while, and never had an upgrade issue before. I don't know if it was those ghost devices, out-of-date drivers and apps, or unused drivers and apps, but something in those categories caused the upgrade to fail.
I hope this helps anyone who has similar issues, and maybe the developers to find the bug.
