Weird issue if part isnt rotated

[keebie81]

I am getting this line printed on the inside of the model unless I rotate the part on the plate. Any ideas why?

[CompoundCarl]

what line are you talking about? i can't see it from the pics

[keebie81]

what line are you talking about? i can't see it from the pics

Sorry for the crude mspaint drawing but the lines in the black area, it goes around the whole inside

I have also attached the stl file.

[JoeJ]

There's a bunch of non-manifold and self-intersecting errors with the STL file you posted. That's likely what's causing the problems.

Have a read here: viewtopic.php?f=8&t=3177&p=13729