My 4 TB Seagate BUP Fast HDD won't mount on my laptop, but it works fine on my Grandma's Ubuntu computer and my friend's PC. It is recognized in Disks, but won't mount, even when I tried the solutions listed here. Disks is telling me that Partition 2 (/dev/sdc2) is "Mounted at /mnt", but I don't see it anywhere. I'm not sure what to do.
EDIT1:
Add output of blkid
sudo blkid -c /dev/null 
/dev/sda1: UUID="d4dd2f23-0638-4364-a0aa-a24d0098ce46" TYPE="ext2" 
/dev/sda5: UUID="NP8qMG-N13f-NSTd-t2dY-0HB2-seND-iIwyKu" TYPE="LVM2_member"
/dev/mapper/ubuntu--vg-root: UUID="1724975b-e000-44f5-a077-1b9ef5fce1e0" TYPE="ext4" 
/dev/mapper/ubuntu--vg-swap_1: UUID="2882828f-b45b-4899-941f-d68a54cdfbfa" TYPE="swap" 
/dev/sdb1: SEC_TYPE="msdos" UUID="3537-6261" TYPE="vfat" 
EDIT2:
Added output of
sudo parted -l
Model: ATA WDC WD5000BPVT-2 (scsi) 
Disk /dev/sda: 500GB 
Sector size (logical/physical): 512B/4096B 
Partition Table: msdos 
Number Start   End    Size   Type     File system   Flags 
  1    1049kB  256MB  255MB  primary  ext2          boot 
  2    257MB   500GB  500GB  extended 
  5    257MB   500GB  500GB  logical                lvm 
Model: Generic- Multi-Card (scsi) 
Disk /dev/sdb: 2033MB 
Sector size (logical/physical): 512B/512B 
Partition Table: msdos
Number Start   End     Size    Type     File system   Flags 
  1    127kB   2031 MB 2031 MB primary  fat16 
  Error: /dev/sdd: unrecognized disk label 
  Warning: Error fsyncing/closing 
  /dev/sdd: Input/output error Retry/Ignore?