Just now, footballmad said:

The primary GPT table is corrupt,

You can try to fix this with gdisk:

 

gdisk /dev/sdX

 

It should show something like this:

 

GPT fdisk (gdisk) version 1.0.5

Caution: invalid main GPT header, but valid backup; regenerating main header
from backup!

Warning: Invalid CRC on main header data; loaded backup partition table.
Warning! One or more CRCs don't match. You should repair the disk!
Main header: ERROR
Backup header: OK
Main partition table: OK
Backup partition table: OK

Partition table scan:
  MBR: protective
  BSD: not present
  APM: not present
  GPT: damaged

****************************************************************************
Caution: Found protective or hybrid MBR and corrupt GPT. Using GPT, but disk
verification and recovery are STRONGLY recommended.
****************************************************************************

Command (? for help):

 

Enter w next to Command + enter, then y + enter:
 

Command (? for help): w

Final checks complete. About to write GPT data. THIS WILL OVERWRITE EXISTING
PARTITIONS!!

Do you want to proceed? (Y/N): y
OK; writing new GUID partition table (GPT) to /dev/sdX.
The operation has completed successfully.

 

Reboot and try to mount again, depending on what exactly was damaged it might work, if it doesn't there's another way, rebuilding each disk, one or two at a time since Unraid will recreate the partitions, but before trying that you first need to fix both disable/invalid disks, then ask for more details.

24 minutes ago, JorgeB said:

You can try to fix this with gdisk:

Damnnnnnnnnn, thanks so much Jorge, it worked on disk21

 

I'll do the same on the other disks.

You really know your stuff and I can't thank you enough.