That texture isn't bugged but misplaced. You should check texture path within mde file.
For gmdrago_mark.mde, the path should be : D:\ymir work\mark_edit\bonedragon_mark.dds
For ridack_dragon.mde: D:\ymir work\pc\common\effect\armor\ridack_dragon.dds
So, you should check those.
Best of luck.