meshmixer tools not working, red lines

[Anonymous]

Why do I keep getting these red lines and meshmixer tools don't work (ie. extrude, smooth boundary, and several other tools)

[MagWeb]

Red lines in MM highlight non manifold issues (more than two faces share the same edge or a "spinning off" face is connected to a closed surface by a vertex). Such issues make most tools fail...

Did you get this result using MM tools before (if yes what was your workflow?) or did you import from another application?

[Anonymous]

I imported an STL file from blue sky bio

[MagWeb]

Can you post the file here (or load it to some file sharing service and send me the download link via PM).

I'll look into it.