Unable to read a code generated AnimationClip with an animator at runtime

Hello everybody.
Here's my issue : I have a code generated AnimationClip in my program, I use an animator override controller to set the animation of my character (I must use an animator instead of the Animation class of unity) and it works in my Unity Editor. But when I make a build (Windows or Android), there is no animation.
My theory is that when an animation clip asset is exported for a build, it is exported so that it can be readen by an animator, but when I set it using code at runtime, it cannot.
Can someone help me here, please ? Thanks in advance.