My LG external DVD/BluRay device no longer works as of Yosemite.
I've wasted a lot of time and money only to determine that this BluRay burner does not work with OS X 10.10.2.
I originally purchased this drive because of the great performance of the device. When the latest OS X version was upgraded, the device failed to work. I spent hours reading forums and chasing my tail. I ordered a new Pioneer device and it worked flawlessly. The only issue was poor performance. So assuming that the first LG BE14NU40 experienced a hardware failure, I ordered a new one. The behavior, of the new drive, is the same the drive fails to read disks on my MacBook.
So heads up ... I'm working with LG to see if there is a firmware update. Most likely LG has not kept up with the enhanced device signing/security in OS X.