Trouble moutning a LUKS device

I am trying to mount an external LUKS-encrypted drive. I followed this tutorial: https://blog.tinned-software.net/aut...-system-start/. When I reboot, I am dropped into System maintenance mode, and my system will refuse to boot until I comment out the applicable line in my fstab file:
fstab line:
Code:/dev/mapper/sdb1_crypt /mnt/toshibahd ext4 defaults 0 2cryptab file:
Code:sdb1_crypt UUID=<UUID> <key-loc> luks