Can't drag a layer into Slot Rack

Hi everyone,

On page 18 of the English Halion 4 manual it says “Programs and Layers can be dragged …into the Slot Rack”.

Well I can drag a Program from the Program Tree into the Slot Rack but I can’t drag just a Layer. Is this a documentation error or is there a hidden setting that has to be changed to allow it?

Here are 2 snips from the manual:

Loading Slot Rack