New site to fix STL files (and it's FREE!)
https://service.netfabb.com/login.php
I just found this one and it works very well. I gave it a really nasty STL file to fix - one with overlapping shells that drives most slicers crazy - and it not only fixed it, but it made the file smaller too.
The same STL file crashed the Microsoft online service. 3D Builder sort of fixed it, but only the Prusa version of Slic3r could slice the result properly. Craftware and Simplify3D could not. But Craftware (my slicer of choice) sliced the file fine after running it through the above service.
翻譯年糕