OS X DVD app does not accept external drive

I replaced my MBP's optical drive with the original HDD and put an SSD in its place and have the optical drive in an external USB enclosure. Consequently, I receive the

A valid DVD drive could not be found. Error -70012

Error when opening the DVD app. I used the alleged fix described here (modifying one of the dvd framework files), but to no avail. The instructions seem to work for most people, so I'm wondering what my problem could be. Has anyone else experienced this issue? I can use VLC and it works just find, but I'm curious if there's a fix for it. I use OS X 10.10.1.