LG System App "Application Not Installed" topic

Since im currently on CM12, im wondering why does LG system applications not install themselves even though you have already fixed the directory and the file with the right permissions?

And, when you tap on the APK and try and install it, it says Application Not Installed

I was curious and tried pulling QuickSetSDK from stock lollipop firmware and pasting it into system/app on CM12 and it wouldnt work one bit