I created a new version ot the layer-combine-with-all-layers script.
This is a complete new script.
Although the menu looks nearly similar, it is as different as the complete script is.
The discription of the function is more logical and the actions give a logic output.
Remember to remove the old layer-combine-with-all-layers.scm from your scripts folder if you have already downloaded it.
The script works for GIMP 2.7+ and is tested in windows 7.