Precious Plated Metal Minimum bounding box

Some help here please. The min. box fits inside my model and seems to be ignoring the rest and says its to small to print. Is there something I'm missing?

Cheers,
Mark

What does the part count say ? Could be some tiny and unwanted loose item there

Part Count is 1 piece.

Then I have no idea - except to carefully check the dimensions it reports. Note that the legend on that image states "too small or large", so it could actually be the maximum 89x89x100mm (3.5x3.5x3.9in) bounding box you are looking at, with a model accidentally oversized by a factor of 10 or so.