Photoshop CS6 won't let me draw on layer masks?
Hi, I've been using photoshop for a few months to a year and I consider myself to be pretty good at photoshop. But this issue, I'm at a loss. So I edit pictures, a lot, of people, and I often add new hair colors or lip colors, and when I do, I add a layer mask so I can draw on pixels if I mess up, but earlier today, that stopped working, and the BRUSH tool just erases (when on the layer mask). It doesn't draw like it did yesterday and the day before, it just erases now. Please, PLEASE help me, I have no Idea what to do. (The opacity is at 100%, the brush is at normal, the flow is at 100%)
