I happened on lollipop 5.1.1 and to one or two app at a time, for some reason the said app just won't show app in application list(and i can't use it)... ahh i can still see it in system/app or system/priv-app
When i attempt to reinstall the package manager behaves like am updating it and i can now use it(surprisingly my data and settings are all there as if i was just updating).
But again if integrate update into system using link2sd or manually move the app files from data/app to system/app or system/priv-app and fix permissions, the app disappears again...
Please help, i really find it pointless to have an anti-thief app on data/ (everybody knows how to reset an android nowadays)..
I had an issue first with "google play services" on Sony C3 (didn't mind that then and decided i wont be integrating its updates to system) and now "avast anti-thief" on Samsung note 10.1, the devices have the same version of busybox installed and are both on stock android 5.1.1.