Good Morning

Very often I'm not able to remove material 'or extrusion boss' after the sheet have been closed corners (corner feat).

Basically, I have to raise the bar in the design tree, to make a recovery, before the corner feat, in order to do an operation outlined as simply as a circle. Otherwise I had simple message:

Construction error: "The operation to fail because of the geometry" or "The function could not cut the body"

I SolidWorks 2013, when I publish some room formerly designed, SW load with no problem, but if I publish a hill, creating upstream closed corners, he does not know rebuilt, although the dimensions are the same .

Do you know this? you know a solution?

thank you very much