I recently downloaded the "Knight of Skeleton Armor" mod from Oblivion Nexus, and I go to where the grave stone to get the armor is supposed to be, but there;s just a giant yellow box. How do I fix this? Is there a way to obtain the armor without having to use the coffin?

Mod Page: http://www.nexusmods.com/oblivion/mods/29527/?

How did install the mod

You likely have to use archive invalidation to get the mod working. If using a mod manager they usually have a tool that does it for. Otherwise you have to use a mod to do that.

Tried Archive invalidation.. I used Oblivion mod manager to install it, other than that I'm stupmed..

Sounds like you have some missing meshes from the mod, which results in a big yellow box like that. Double check the installation.

I looked at the file and there's two options, one is the OMOD install and the other is manual install. Which file did you download?