I have been trying to fix my model for a week now, with no avail.
Rhino mesh edit said it was all good meshes.
Net Fab Basic has no issues,
All wall thicknesses are within the limits ranging from 1mm to 3mm
First hit, using NetFabb's analysis tool;
154 boundary edges
Using NetFabb's repair tools results in the same, exporting the repaired part and re-loading results in the same.
2nd hit, using NetFabb cloud service (http://cloud.netfabb.com/) returns a printable model with two shells - this means all of the 187 shells in the original model have been reduced to the least amount of seperate shells possible and that you have two seperate parts in your model. This model is attached.
If you intended two parts then ignore this - identify the loose part & move it slightly to overlap the main part, then use NetFabb Cloud service to merge the two shells into one (upload file then download repaired file)and you should be good to go.