Mesh deforms itself when an animation has been associated to it

Hi, I met this problem.

I imported a FBX in UE4.
The model imported is rotated by 90 degrees on the Y axis, if I try to reimport the same, modifing the rotation, nothing happens.

But the problem is another one.
When I associate an animation to the rotated model, the mesh goes crazy!

ce281d2c682382c9e2bfdc4bc8011442c18fbc26.jpeg

Some help?
Thanks.