Vertex animation on scabbard

[Runer88]

Hello everyone. Recently I have started making weapon models for MountBlade Warband.  I made a sword and I scabbard for it. Later I have learned that I have to make a vortex animation. All good. I have made one. And the result on the last frame was this... https://imgur.com/gallery/63tNm56


P.S. I have found a solution for this issue.