Effects Don't Always Work

[jimlolo]

Sometimes when I load a photo, I can adjust the Brightness. But other times, like shown below, it can't be. Why?

[S_Gans]

In your image, you're currently focused on the MASK portion of your adjustment layer. Instead, focus on the little Brightness/Contrast icon (to the left of that mask, on your layer) and you can adjust the actual image.