[Edi]

If you mistyped the armor name when modding it, I would presume. Some of the armors don't have capitalization of every word (mostly some of the rusty armors, Rusty Ring mail Hauberk, Rusty Scale mail Hauberk and Rusty Chain mail Hauberk). They should have the word "mail" capitalized, but don't, so if you're using one of them, it's probably the problem.

I'm actually going to have to fix that for my W&A database, because I apparently have made an error here, typing everything capitalized.

I'm also not sure if you need to add _ in place of spaces, but I do not expect that to be the case.

Edi