Alludo USER to USER Web Board

I'm using the new Pro X2 and trying to overlay a shot and control the opagueness. The manuel indicates that this can be controled by "dragging the Transparency slider". I would be only too happy to do this, except that the slider tool itself seems to be transparent, as I cannot find it in any window.

With the clip in any of the overlay tracks click on Mask/Chroma Key.

The trancperancy button is at the top left hand side of the Atrribute panel. The button with a triangle pointing down to a dash/line is the transperancy slider

Thanks for revealing the invisible slider to me and probably other editors.