eraser doesn't work in layer mask
I've been using PSE 13 for a few years now, last week the eraser stopped working when I'm erasing in a mask layer. The eraser works OK in a picture, or in a layer, but the moment I try to erase in a layer mask, it just doesn't work any more.
I didn't change settings..... Tried restore tool settings, tried a new install of PSE 13, nothing helped!
What can possibly be wrong in the program settings related to the layer mask that prefends the eraser from working??
Thanks for any help

