Did you save the STL as ACSII? If you saved it as binary it will give problems.
@juansan995 Yea i did. I did nothing special. Just opened the STL and saved it. It took me around 30 seconds to open the STL. I have uploaded the S4 home work STL as SW file so you don’t need to open the STL. S4_home_work_model saved as SW 2016 file
I hope that it helps you!