The tittle says it all. For some reason the slicing process makes additional layers within emtpy space, making some sort of spaghetti 'glitch'. In the first pic, it's another model, in which happened the same but I wasn't present at the moment it happened so I didn't noticed. In the second pic you can see the 'spaghetti glitch' that has been taken out during print; ninja style.
First I thought it was an export/import problem. I couldn't visualize the processing of layers in CURA, I don't know why. but it did showed this filled gap. And in Repetier Host I could find which layers where being filled up with this problem (layers 103~108).
I'm attaching the file.
Any idea why this is happening? Thanks in advance.