UPDATE: Nope, the animation problem is back. Basically, I made my mtidle.fk animation in the skeleton Blender file, and exported it, it worked fine. But, since I needed to make more animations, I saved as a new Blender file, and imported my mesh and parented it to the skeleton, as I needed to see my mesh for the more complex animations. After, I made an animation and exported it from this new Blender Animations file, however, the newly created animations are rotated 90 degrees roll. The only reason I could see why this is happening is that parenting my mesh to the skeleton has somehow thrown the rotations off. I reset the transformations on all objects and all bones, but the problem still persists. Even worse is that, in the buggy animation files, setting all the rotations back to zero manually in nifskope does not make any difference. Also, I managed to figure out how forward movement works, but this random rotation error is annoying me, because I don't want to have to restart my animations, or have to make them without being able to see my mesh being animated.