I made a series of meshes for a suit of armor, but I'm having trouble because the chest, when equiped in game, is invisible. Every other part of the armor, pauldrons, greaves, ect. are showing up fine on the character. Is there something I'm missing?

This might be a bit late for a reply, but I have encountered similar issues when the nodes in the .nif file of a chest mesh were not named correctly. I advise you to open your chest mesh in NifScope, and one of the chest meshes from the vanilla game or another mod, then compare the naming scheme of the nodes and make sure that yours matches the reference.

That's not it... Does it matter if it's a multi material mesh?