nanoDLP

Hello all,
I created a mask with blueprint paper, adjusted it in Gimp and exported it as a .png file. When I try to add it as a new mask in "projector calibration" "projector mask" "add mask" the preview image doesn't update. It shows what I assume is a default mask, the image doesn't change to my new mask. How do I know if my new mask is being used, without wasting a bunch of time with doing endless test prints?

Also when I go into the 3D plate making function and add several .stl objects on one plate. Then save as a plate often it crashes and I have to re layout the plate. If I am able to save as a plate the option to apply a mask to that plate doesn't come up as an option. The option to apply a mask on a plate only shows up when it is just one .stl object on that plate.

Any ideas out there? Is it me?