I need help

[Lampinenalex 0]

Can anyone help me, what does this mean?

when I slice it, and I look at the preview it only show the sole of the shoe. Can anyone hell?

[Labern 774]

Hi there. 

 

It looks like the model is not a solid model and there may be an open face or have errors in it. 

Some programs like SketchUp allow you to draw faces that don't form a solid model. Which means that if you were to fill it with water it would leak. 

[GregValiant 1,112]

You might be able to fix it using this repair site https://formware.co/OnlineStlRepair.  Upload the file and when it's ready you will get a report of the errors and hopefully the file will be fixed (not all can be repaired).  Then download the repaired file.  I've used them a few times with good results and it's free.