We had a bit of a terrifying experience today with Altium.
PSAMake sure you turn on your Permitted Layers rule in your DRC. If by chance you were to change the layer of lets say a diode to "Silkscreen Top" and then you ran your output job to generate gerbers. Altium will
BACK ANNOTATE to your layout

. It will move your pads from whatever layer they were on to silkscreen. Completely destroying your layout. You cannot undo this, but rather have to revert to a previous save. In your gerbers it is very obvious that the mistake is there.
We however ran into a situation where our customer was generating final documentation from the design. They do not review gerbers like we do and FABs were ordered with missing pads and messed up silkscreen.
I have to ask the question: Has anyone ever had the need to place a component on a layer that isn't top or bottom? I find myself asking why it is even an option to place a component on a layer like silkscreen top...
FYI we are running AD19.1.7 not sure if the issues exists in all releases.
~Bryan