I rely heavily on the Oil Paint filter for my artwork. It's been working fine until a few days ago. All of a sudden when I invoke it the preview window is black. If I click the hand icon in the window it DOES show the image I want to work on but only so long as I hold the button down. I've checked to be sure that I haven't changed from RGB to some other format. I haven't. It's still RGB and no other settings have changed. Why would it suddenly go on strike like this? More important, what can I do to get it to work?