I have seen this topic before, but not seen an answer.
If I download an STL from Thingiverse to incorporate into one of my own designs, I can't do anything with it, such as snap to object etc, unless it is converted to solid first. If I try and convert it to a solid 123D Design on PC always freezes or crashes.
I tried converting to solid in Meshmixer, then export as STL, but when I import that into 123D Design, it is imported as a mesh again. I double checked to make sure I was exporting the right object in Meshmixer, and I was.
Any help would be much appreciated