Hello to all i have question about Cura

[MakkeLeon 0]

vierkant_test (5).stl

I just want to print this open square but it print a complete square.

WHY it fills in the blank spot too?

[gr5 2,229]

I looked at your STL and it's fine.  It's manifold and the normals are facing the right way.  The only thing I can think of is that in "mesh fixes" setting in cura you have "remove all holes" checked.  Uncheck that.  In fact uncheck everything in "mesh fixes" section.

 

By the way when I sliced it, it was fine.

 

If you still can't figure it out, do a "file" "save project as" and post the project file.  That will have the model but also many other things including your profile, printer settings, scaling factor and rotation of part, material chosen and more.