JorgeB

This suggests a problem with the zfs filesystem, see if it mounts read-only, with the array stopped type:
 
zpool import -o readonly=on disk1  
If it works, start the array, disk1 will show unmountable in the GUI, but the data should under /mnt/disk1, then backup and re-format.

According to the screenshot the device is not formatted NTFS. You can re-format with windows, remove the partition first, then create a new one and format.

Check if the USB is still the first boot device, if it is, the flash drive will probably need to be recreated, or replaced, and you won't be able to do that remotely.

Jun 21 07:59:24 RAWBHL-NAS emhttpd: error: mkmbr, 2196: Device or resource busy (16): ioctl BLKRRPART: /dev/sdc  
Device is reporting busy, reboot and try again, that is usually enough, but if it fails again post new diags.

This is normal, with bridge disabled it can only use macvlan.

Try uninstalling the S3 sleep plugin.

Check the flash drive shares folder, lokks like there's Dowloads and downloads cfg files

Possibly there's some compatibility issue with that board and the kernel on v6.12, suggest remaining on v6.11.5 for now, then retest with v6.13-beta when it's out, it should be out very soon, that release it will have a very different kernel than v6.12.

Unraid driver is crashing, this is almost always a hardware issue, start by running memtest, also update to latest stable.

Formatting deletes everything, if you have a appdata backup you can restore it and recreate the docker image:
 
https://docs.unraid.net/unraid-os/manual/docker-management/#re-create-the-docker-image-file
Then:
https://docs.unraid.net/unraid-os/manual/docker-management/#re-installing-docker-applications
Also see below if you have any custom docker networks:
https://docs.unraid.net/unraid-os/manual/docker-management/#docker-custom-networks
 
 

Plex (and other containers) have been know to crash whole servers, you can try asking in the Plex support thread for the container you are using, if there are any current known issues.

Not really, but it's OK for powerline, with gigabit it should be around 300GB per hour.

Known issue of the MX500, disable monitoring that attribute:
 
 

Those are not recommended, avoid splitting a SATA plug into more than 2 plugs, Molex can usually be split into 4, but if possible also just 2.

I would suggest recreating the flash drive.

Try a new power cable, or swap with a different disk.

Diags are still not working correctly, so other things also may not, recreate the flash drive again, but this time don't restore anything from the backup initially, then see if the GUI works.

Yeah, that disk needs to be replaced, so you cannot rebuild disk3, but disk3 and parity look, so most likely they got disabled due to a power/connection error, I would try the following:
 
-Tools -> New Config -> Retain current configuration: All -> Apply
-Check all assignments are correct, unassign parity2 since that one is bad
-Check "parity is already valid" next to array start button and start the array
 
Disk3 should hopefully mount, if it does run a correcting parity check, if it doesn't, post new diags.

Something is causing the data corruption, and 9 times out of 10 it's RAM related, but it could be a different issue, after any change you make, scrub the pool, then reset the stats, and keep monitoring for more corruption errors, if new ones appear there's still a problem, more info below:
 
https://forums.unraid.net/topic/46802-faq-for-unraid-v6/?do=findComment&comment=700582
 

That's normal, but the emulated disk is mounting now, look for a lost+found folder, if all look good get a new disk and rebuild.

Recreate de stock flash drive again, but then restore only the /config folder from the old one.

Jun 12 00:23:05 Tower kernel: SQUASHFS error: xz decompression failed, data probably corrupt Jun 12 00:23:05 Tower kernel: SQUASHFS error: Failed to read block 0x270a57c: -5 Jun 12 00:23:05 Tower kernel: SQUASHFS error: xz decompression failed, data probably corrupt Jun 12 00:23:05 Tower kernel: SQUASHFS error: Failed to read block 0x270a57c: -5  
These usually mean a flash drive problem, you can try redoing it, if the errors persist, you will need to replace it.

One of the disks is failing to identify:
 
Jun 18 18:31:10 Tower kernel: ata10.00: supports DRM functions and may not be fully accessible Jun 18 18:31:10 Tower kernel: ata10.00: ATA-9: WDC WD140EDGZ-11B1PA0, 85.00A85, max UDMA/133 Jun 18 18:31:10 Tower kernel: ata10.00: qc timeout after 5000 msecs (cmd 0xef) Jun 18 18:31:10 Tower kernel: ata10.00: failed to enable AA (error_mask=0x4) Jun 18 18:31:10 Tower kernel: ata10.00: 27344764928 sectors, multi 0: LBA48 ÿ� Jun 18 18:31:10 Tower kernel: ata10: SATA link up 6.0 Gbps (SStatus 133 SControl 300) Jun 18 18:31:10 Tower kernel: ata10.00: supports DRM functions and may not be fully accessible Jun 18 18:31:10 Tower kernel: ata10.00: ATA-9: WDC WD140EDGZ-11B1PA0, 85.00A85, max UDMA/133 Jun 18 18:31:10 Tower kernel: ata10.00: qc timeout after 15000 msecs (cmd 0x2f) Jun 18 18:31:10 Tower kernel: ata10.00: Read log 0x00 page 0x00 failed, Emask 0x4 Jun 18 18:31:10 Tower kernel: ata10.00: NCQ Send/Recv Log not supported Jun 18 18:31:10 Tower kernel: ata10.00: Read log 0x00 page 0x00 failed, Emask 0x40 Jun 18 18:31:10 Tower kernel: ata10.00: 27344764928 sectors, multi 0: LBA48 NCQ (depth 32) Jun 18 18:31:10 Tower kernel: ata10.00: Security Log not supported Jun 18 18:31:10 Tower kernel: ata10.00: Features: NCQ-sndrcv Jun 18 18:31:10 Tower kernel: ata10.00: failed to set xfermode (err_mask=0x40) Jun 18 18:31:10 Tower kernel: ata10: limiting SATA link speed to 3.0 Gbps Jun 18 18:31:10 Tower kernel: ata10.00: limiting speed to UDMA/133:PIO3 Jun 18 18:31:10 Tower kernel: ata10: SATA link up 6.0 Gbps (SStatus 133 SControl 320) Jun 18 18:31:10 Tower kernel: ata10.00: supports DRM functions and may not be fully accessible Jun 18 18:31:10 Tower kernel: ata10.00: qc timeout after 15000 msecs (cmd 0x2f) Jun 18 18:31:10 Tower kernel: ata10.00: Read log 0x13 page 0x00 failed, Emask 0x4 Jun 18 18:31:10 Tower kernel: ata10.00: Read log 0x00 page 0x00 failed, Emask 0x40 Jun 18 18:31:10 Tower kernel: ata10.00: NCQ Send/Recv Log not supported Jun 18 18:31:10 Tower kernel: ata10.00: Security Log not supported Jun 18 18:31:10 Tower kernel: ata10.00: failed to set xfermode (err_mask=0x40) Jun 18 18:31:10 Tower kernel: ata10.00: disable device  
Swap cables between both and see where the problem follows.

If you have/had any custom networks try recreating the docker image, since that will delete them.

I meant a degraded link, that can happen at anytime, try rebooting or using a different USB cables, but I'm afraid I cannot really help troubleshooting USB enclosures, and they can be a lost cause.