This particular model is made up of three meshes inside the .x file. The trunk, the branches and something called a "firespot". The firespot has no normals but the rest of the model does. This causes confusion when agk tries to render it with a normal map as it cant apply a normal map to a model mesh which has no normals.
This particular .x file is saved as an ascii .x file - this means you can open it as text and see all the parts of the model. You can literally browse through the vertices and texture coordinates and normals. It also means you can go into it and simply remove the firespot parts (the frame, vertices, mesh, uvs and animation) then save it.
This then allows you to set a normal map to the object in AppGameKit and it then doesnt generate an error in agk when attempting to add a normal map and it renders it.
I assume the firespot was originally meant for where a fire would start or something else? Its just a single triangle in the model that appears to not really be used. Its that annoying little bit that causes the issue.
Also - as the file shows...technically there are some animations as you can see the keyframes but they dont do much
