FBX -no animation data in unity. 100% ok when brought back into maya.

Hi,
We have a ton of characters and animations in our game. With one new character we can't get unity to see the FBX animation data and have no idea why.

-Everytime we import the fbx or change a meta file setting unity crashes with an Access Violation Error.
-After rebooting the animation says no animation data.
-after exporting many times we have had the animation data be recognized but no bone rotation in the preview.

-Reimporting the FBX back into maya the animation plays as expected....

FBX -no animation data in unity. 100% ok when brought back into maya.