Our group is looking to have rough plates made with three amounts of roughness (0.5 mm, 1 mm, 2mm amplitude). I generated the rough surfaces in matlab and then exported this surface as an stl from matlab into solidworks. There were several problems so I ran import diagnostics and it fixed several things. I was able to fix some other faulty faces by deleting the face, using surface fill, and then knitting it together. However, there is still one aspect of the drawing which I cannot fix. Every time I run "Check" it finds an open face on the corner of the drawing. I have tried to delete the faces and then close them up but every time I try and do this it adds another open surface. Any idea on how this can be fixed?