After the model had been repair by Preform (with Netfabb integrated), is it 100% error free and ready to be printed? The reason I’m asking this is because I had one particular file that was fixed by Preform and already fail twice when printed. I never had any problems with other files and they all had been repaired by Preform.
The model repair step is just checking the integrity of the mesh. There are a number of other things that go into getting a successful print.
You can double check the integrity of the mesh after it is imported by going through the model with the slice plane, but I would suspect the problem is probably something else. For example, an unsupported minima.
Meshlab is my first check for an .stl that didn’t come from my CAD software. It makes bad normals particularly obvious. But it knows nothing about requirements for the print process.