Rendering in 2.79 produces a blank image - ok in 2.78c (solved)

Problem: I have a blender file with two layers and the second layer is de-selected in the Layer menu.
When I render using F12 everythin renders fine.
However, when I render an animation and/or from command line only a blank is rendered (I presume its the un-selected layer). Same file renders fine in 2.78c.
If I delete the unused layer all goes well in 2.79.

koe.blend (591 KB)

check, understand your Compositing (Node Editor, Alpha Over…) :wink:
you can also simply deactivate Compositing from the Properties > Render > Post Processing