Problem with animations

Hi, I have a new problem. Now there is thing with Blender 3D. I have exported my Rocket.blend as .fbx file with 2 animations inside. when I have imported rocket.fbx to UE4, all stays good but animations. Literarly, they are, they have their names and files, BUT have no picture like they are empty. If I open them, the strange thing happens - frames are switching, but nothing is seemed. When I use them on skelet skelet disappears.
Is here any guru, who can help me, please? hope so.