Black spots appear when exporting 2D window in substance

[Forrestfofos3]

Hello There, When exporting my textures from Substance Painter sometimes I get an entirely black texture or black spots/pixels on the exported texture. What is causing this and how can I fix it?

Sometimes I have to export multiple times just to get a clean texture. 

Here is an example of what is happening https://gyazo.com/16beac92d19cd07fa6b5bc0799532380

[Alvin251158188dxb]

Hey, don't know if you ever resolved this but if anyone else finds this thread with the same problem, sometimes changing the resolution of the export from 4K to 2K fixes it.

Sometimes the Base Colour Map only works if it's on 2K, but the normal map doesn't, and then vice versa where if I export on 4K, the Normal Map is fine, but the base colour isn't.

Really weird work-around, but this is what worked for me.