when attempting to paint on a photoshop layer in the layer window of 18.2.1 to quickly patch an image without opening photoshop, paint tool would not allow me to alter the brush. i just wanted to take it down from 115pt to 20pt, but all attributes were grayed out... I haven't painted in ae in years because the tool is in serious need of update, but i opened up AE 17.7 to see if the error was there too. That version not only worked fine but by launching and using that brush tool, the current version became functional. perhaps this current bug will inspire you to update the tool to be more like photoshop's, with the temporal write on appeal of ae.