Help needed! Highlighted box larger then part!

[minipie172 0]

I am trying to print parts but the box of the highlighted piece is much larger then it needs to be, how do i fix this box. it doesn't spice because Cura thinks the part is that large. How do I fix the dimensions (of the box - not the part) of the piece so I can print it. I don't know how these boxes are getting so large.

I used 3D Builder on windows to make the parts but never had this issue til recently. 

[peggyb 169]

make the z value 0, does that help?

 

[Framar 38]

There is probably something wrong with the 3D model. If you want I can have a look at the STL and fix it for you. Can you post it here ?