Joined the dev channel, system appared to be approved. Ran the update, rebooted and got an green screen showing inaccessible_boot_device.
Windows booted into troubleshooting mode after having me choose language. None of the options there worked at all, so I restarted.
Booting up the same happened, but I was prompted with what was a slightly different troubleshooting menu. Did not think much about it. Tried the rollback options etc there, but no luck. Was about to try the reset system option when I noticed an option to change boot option.
There I saw Windows 10, and an unnamed option. Chose the latter and rebooted. Same error, and back to the first troubleshooting menu. This one does not have the option to change any boot selections, and the tools do not work at all, not just unsuccessful, but they just don't work.
Running CMD I noticed none of the drives being available at all. So it looks like my Raid Array is unavailable after the update.
I made a Windows On The Go USB stick and booted this, and the drives were gone, naturally. Installed the Raid drivers on the stick, and the Array is now visible to the USB installation, so the Array is working. I can access the drives, and I see the OS drive as well.
So, I'm assuming the upgrade to W11 botched the Raid Drivers and thus W11 can't see the disks.
Now, if anyone knew a way to insert these raid drivers to the OS drive from the Windows On The Go USB drive, it could possibly be possible to save the day. Not sure if this is possible though.