It doesn't crash on direwolf or galaxy. It only crashes since we updated the bevo modpack. So it is a mod issue
Server crash on BTP 10.8 cauldron - MFR Grinder or Slaughterhouse · Issue #716 · BevoTechPack/BevoTechPack · GitHub supposedly Fixed in build 210 of cauldron.
It seems there is still a timed mechanism that removes the grinders. Mine vanishes around every hour ...