Well, I'm not sure what to tell you then, other than to suggest you uninstall and delete the entire folder for Mount&Blade (normally in "C:\Program Files\") and then run the .711 full installation (be sure of the version, and the "full installation" copy) before then installing the mod.
If, as you say, you've basically done that, it should work fine and not be giving you any problems. The error you're getting indicates it's having a problem with the new material definitions, which should only occur if the game version (and core files) are below .711, or you have installed another mod which overwrites core files in the CommonRes or Textures subfolders within the root Mount&Blade directory.