This bug causes some annoyed visual glitches.
Here is the fix.
open "spell.txt"
mgr.defineSpell( "dm_co_windstoss", {
eiStateName = "cSpellCast",
fxTypeCast = "FX_DM_WINDSTOSS_C",
fxTypeSpell = "FX_DM_WINDSTOSS",
---missing: fxTypeCastSpecial = "FX_DM_WINDSTOSS_C"
duration = 0.000000,
animType = "ANIM_TYPE_SM06",
animTypeApproach = "",
animTypeRide = "",
animTypeSpecial = "ANIM_TYPE_RIDESM06-SPECIAL",
...
})