Gradient Editor now not accessible
I have Adobe Photoshop CC 20.0.1 and have just struck some issues with the gradient editor not appearing.
So when I select gradient from either the adjustment layer area or clicking Image>Adjustments>Gradient Map, on clicking the dropdown to select a gradient, the editor does NOT open.

How is it possible to reset this tool so it works correctly? It was fine earlier this morning, but now won't bring up the Gradient Editor window at all
cheers

