I have been working on copying a Laurence Esnol painting for about 1 week now and for whatever reason the erase tool has stopped working. I'm drawing the face of an adult female, I remember having to redraw it due to having too few layers assigned(the lines layer doubled as my sketch layer), the erase tool still seems to work when I draw single strokes as well as for the top half of the face, but when I attempt to erase inaccuracies at the chin it doesn't work.
SPECS: HP 255 G6 Notebook
AMD A6-9220 RADEON R4,5 w/ 2 compute cores 2c+3g @2.5GHz
8 GB of RAM