JorgeB

Make sure the LSI is using the latest firmware, if that doesn't help make sure the disk is spinning up, in case it's being powered differently, if still nothing, it could be a compatibility issue.

There are constant crashes logged, start by running memtest.

Disk is not giving a valid SMART report, if you have already replaced cables it's likely a disk problem:
 
Read SMART Data failed: scsi error badly formed scsi parameters  

You can always do a manual update:
 
https://docs.unraid.net/unraid-os/manual/upgrade-instructions/#manual-upgrade-or-downgrade

You can, the array will be unprotected until the sync is done.

You can try copying only super.dat and the pools folder from the old flash, that would take care of the assignments, and it should not cause boot issues, but if it does see here:
 
https://docs.unraid.net/unraid-os/manual/changing-the-flash-device/#what-to-do-if-you-have-no-backup-and-do-not-know-your-disk-assignments

Disk1 is still unmoutable, there may be a device problem, run an extended SMART test on it.

emhttpd crashed, you will need to reboot to get the WebGUI working, type reboot in the CLI, if it doesn't reboot after 5 minutes you will need to force it.

That's not how you should do it, since that won't be fixing the emulated disks, and if the disk were not being emulated it would make parity out of sync.
 
The GUI option should work, but if it doesn't, start the array in maintenance mode and type
 
xfs_repair -v /dev/md13p1 and
xfs_repair -v /dev/md14p1  
 

The zfs pool is corrupt, you should backup and re-format, see if it mounts read-only without panicking, you can then backup.
 
Reboot the server, don't start the array, and type:
 
zpool import -o readonly=on cache  
If OK, start the array, cache will show unmountable in the WebGUI, but the data will be under /mnt/cache, backup and then re-format.
 
 

Use -L

Yes.
 
Copy the file replacing the existing one.
 
It is.

This means you need to update Unraid to latest release first, if you are on an expired trial contact support so they can extend it, but do it using the form, contact options within the OS are apparently not working.
 
P.S.: you can also manually update to v6.12.9 and then activate your key, and that can be done even with an expired trial.
 
 

That suggests the SATA controller is being passedd-throught to that VM, please post the diagnostics.

That should not happen when adding a new device, something weird still going on there, try this:
 
Unassign the second nvme device, also wipe it with wipefs -a, set pool slots to one, start array with just the 1st device, stop array, set pool slots back to 2, re-assign 2nd device, start array, if it doesn't work post new diags.

Just delete that file as well, you likely had some flash drive corruption.

You have two NICs on the same subnet, change the 2nd one to a different one, also remove the gateway from the 2nd NIC, only eth0 should have a gateway configured.

See the root share option with the UD plugin:
 
 

As long as you existing appdata is still present it should keep everything as is.

You need to run the mover, changing just the share settings won't move anything, see here for how to configure the share settings:
 
https://forums.unraid.net/topic/46802-faq-for-unraid-v6/?do=findComment&comment=511923
 
 

Pool metadata is damaged, you will need to recreate the pool and restore the data from a backup.

You must unmount that first:
 
umount /temp  
You can then try reformatting just the good drive.

Try using an exclusive share (or disk share), it will bypass FUSE.

SMART test passed so the disk should be OK.

Can't see if the docker image is on the pool or disk1, since share system exists on both, still both should have enough space, try recreating the docker image:
 
https://docs.unraid.net/unraid-os/manual/docker-management/#re-create-the-docker-image-file
Also see below if you have any custom docker networks:
https://docs.unraid.net/unraid-os/manual/docker-management/#docker-custom-networks