Error when applying bones to mesh

I have my mesh set up as well as my bone structure, as created following a blender tutorial on blendercookie, but whenever I go to object mode, select the mesh, right click the armature, control p -> (the weighted option that’s exact name is escaping me), I get an error up in the corner of my screen that says Bone Heat Error, and says that is couldn’t figure out one or more of the bones. When I go into pose mode the armature is still not applied to the mesh and moves without it. I’m not sure what to do, any help would be greatly appreciated.
Below should be an image of my mesh and armature, just in case it helps.

Common reasons for bone heat weighting to fail are:

  • Duplicate vertices in the mesh
  • Internal faces in the mesh
  • Strongly asymmetrical topology in the mesh
  • An off-center mesh and/or armature. Make sure the origin point of each of these is on a common central plane.

If none of those suggestions fixes the problem, post your .blend file so we can check directly.

There are definitely internal faces in this mesh… Ill figure out how to get rid of them. Thank you for your help!

You can use Alt+B to cut view sections through your model, this makes it easier to get at faces that are inside. Alt+B toggles back to full view when you’re done.