Substance Painter doesn't support non-official Apple configurations, meanings any part (for example the GPU) that has not been sold originally by Apple may not work properly with the software.
In case glitches, crashes or even artifacts appear on Mac OS when running a custom GPU with custom drivers a workaround may be to delete the properly list files related to the application.
To do so :
- Navigate to : ~/library/preferences/
- Remove any *.plist files starting with com.allegorithmic
It is also advised to remove the general application preferences : Application preferences location