Error unlocking /dev/sdb1: Failed to activate device: Operation not permitted

Question

After updating my PC to Ubuntu 18.04, I'm not able to mount my encrypted disk anymore.

Error unlocking /dev/sdb1: Failed to activate device: Operation not permitted

NAME                          FSTYPE      LABEL UUID                                   MOUNTPOINT
sda                                                                                    
├─sda1                        vfat              8219-4270                              /boot/efi
├─sda2                        ext2              bff8fdc5-c265-4eee-acad-0db6e4f44214   /boot
└─sda3                        crypto_LUKS       a32f0a9f-beef-4fb3-a0d6-f0e6926e37a3   
  └─sda3_crypt                LVM2_member       c0dGw1-IO3l-fWRN-0r2F-rrsj-pDfQ-6IXxPZ 
    ├─ubuntu--mate--vg-root   ext4              324101be-d34e-45c1-a902-43374373c3a6   /
    └─ubuntu--mate--vg-swap_1 swap              70eadd83-c37c-4f56-b41d-2956d296d85a   [SWAP]
sdb                                                                                    
└─sdb1                        crypto_LUKS       8e619d1d-9fb6-4314-923f-06bb64d86031   
sr0 

Solution

I got this error when I mis-typed my password.

Entered Correct password and my drive mounted just fine.

Comments

[qwertbert23]

Yeah… I've tried the correct passphrase several times…

[Brent Bradburn]

An unhelpful message when the only problem is a wrong password -- but that was the case for me too.

[Tullo_x86]

Ah, Caps Lock, my old nemesis...