HaloMods "Classic" Read-only Archive

Hey i really need help with this when in tool i press "tool collision-geometry garage" and then i get all these ### ERROR Open Edges, i went to go look at the tutorial but when i went to do the STL Check i see them and im still confused on how to fix the open edges, can someone clearly explain this to me or if there is another way?

please i really need help dont let this topic die

I beleive each collision model edge mush share two triangles/polygons
So it is a closed object, hope that clarifys it