Herbie

Redownloaded and been playing through v12 but it seems like a crash occasionally occurs either at Carotos Mountain, grass patches in Sheridan Arena or Amethyst Cave. When im walking just a few feet in either location this pops up and closes the game and I have installed the rejuvenation modular modpack and followed the instructions. But the same thing keeps popping up so any advice on how to fix this.