If I click on "..." (right to "Effekt1" "Farbverlauf", out of window)
I get the "Farbverlauf" (translation: color gradient) window.
But if I change from "Radial" to "Linear":

and click "OK" the color gradient type of my choosen object isn't changed.
It's only changed in the little "Farbverlauf" preview window.
My object has a radial color gradient furthermore.
I have seen that new objects are now created with the
choosen linear color gradient. But I want to change the
color gradient type of my existing object from
"Radial" to "Linear".
So how can I change the color gradient type of an
existing object or isn't it possible?