Windows 10 ( with Bootcamp on MacPro 2013)
GPU : AMD FireProD700
Broken: 2.78c, 2.79 test build
Short description of error
Pen pressure from Wacom Cintiq Pro 16 cannot be detected. It works with Intuos Tablet.
Tested in GreasePencil, Sculpt mode, Texure Paint mode.
Exact steps for others to reproduce the error
You need to have Wacom Cintiq Pro 16, but it might be able to reproduce the issue with other graphic tablets as well.