Encrypted Drive Unable to Mount. dm_mod missing

[jsmith]

Whenever I try to mount a LUKS encrypted external HD, I get the following error message:

***
/dev/mapper/control: open failed: No such device
Failure to communicate with kernel device-mapper driver.
Check that device-mapper is available in the kernel.
Cannot initialize device-mapper. Is dm_mod kernel module loaded?
***

From what I understand this means that the dm_mod kernel isn't installed. Is there any fix for this? I've installed package updates, but have been unable to fix the problem.

Any help is appreciated.