Material duplication and renaming happens

Since I struggle with Play failing, I try to change various things in order to locate the problem without luck so far.

But it seems that each time I press Play, Armory generates a duplicate material for each material used, by naming them
Material.001_armskin_armskin_armskin… and so fortth.

This is creating a mess in the material list and is still there on restart and reload of the project. Each has zero users except the last generated “armskin” material.

I am not sure if this is an issue or something I do wrong regarding packing, which is set to “auto pack”…