I have the same problem, it was perfectly working yesterday and shutdown brutaly, i change my computer recently to fit the spec of your soft because it was not working on my old corei5 and radeon 5000, so now my spec is corei7 and Nvidia gtx 1050 GPU damn i hate to be slave of that (zbrush don't have this problem...), so i wan't to bring back all my purchase librairie, to the new computer and finaly work with painter. Hope wa won't have to wait to long for that, especialy with the Adobe news, that make worrie legit from part of your user.