AnimationClip.framerate equals zero

What could be the reason I get a zero frame rate from a particular animation clip ?
Every other animation clip I test gives me the good frame rate, only one returns me zero.

Thanks

Can you post the code you are using to get the framerate? (It’s unlikely to be the cause of the problem but worth checking out nevertheless.) Does the animation have any visual problems when you view it or do you see any error messages in the console?