HHHEELP! Correcting skin tones in the 26 version

Guys help. Correcting skin tones used to be sooooo easy. I always just drew a mask around a part of the skin and then adjusted while looking at the Vectorscope. But I haven't done it in a while and suddenly the mask tool under opacity is just gone??? How am I supposed to correct skin tones now? This is beyond frustrating. I feel like a beginner again. Please help