I have now run afoul of this problem as well... the .apk is in the system folder, I can use the dialer code 3845#*801# to access the menu, but when it comes up all I see is null as the first and only item in the list. If you tap on null, it pops up a small box that says 'Not Implementation'. This is on OptimusG3 ROM V1.3.2 with the default kernel.
The thing is, this worked just fine all morning. Now, after lunch, poof! All gone.
LG - D801 | G2
SGH-I747 | Galaxy S III <- Gorilla glass why u no impact resistant!?
SGH-I897 | Captivate <- It just won't die. Running Kit Kat on 512MB!
SGH-T919 | Behold <- The great pretender. Original Touchwiz...
SGH-E720 | <- The great flipper...
SGH-N105 | <- Keyboard cover, yo, keyboard cover!
Nokia 8290 | <- The plastic fantastic, you gots to sqeeze it to sees it!