It'd be nice if this code in grue.lua component gets changed from this current code code
Spoiler
function Grue:OnUpdate(dt)
if self.nextHitTime ~= nil and self.nextHitTime > 0 then
self.nextHitTime = self.nextHitTime - dt
end
if self.nextSoundTime ~= nil and self.nextSoundTime > 0 then
self.nextSoundTime = self.nextSoundTime - dt
if self.nextSoundTime <= 0 then
if self.soundwarn ~= nil then
self.inst.SoundEmitter:PlaySound(self.soundwarn)
end
self.inst:DoTaskInTime(self.warndelay, self.inst.PushEvent, "heargrue")
end
end
if self.nextHitTime ~= nil and self.nextHitTime <= 0 then
self.level = self.level + 1
self.nextHitTime = 5 + math.random() * 6
self.nextSoundTime = self.nextHitTime * (.4 + math.random() * .4)
if self.soundattack ~= nil then
self.inst.SoundEmitter:PlaySound(self.soundattack)
end
if self.level > (self.resistance or 0) then
self.inst.components.combat:GetAttacked(nil, TUNING.GRUEDAMAGE, nil, "darkness")
self.inst.components.sanity:DoDelta(-TUNING.SANITY_MEDLARGE)
self.inst:PushEvent("attackedbygrue")
else
self.inst:PushEvent("resistedgrue")
end
end
end
to this
Spoiler
function Grue:OnUpdate(dt)
if self.nextHitTime ~= nil and self.nextHitTime > 0 then
self.nextHitTime = self.nextHitTime - dt
end
if self.nextSoundTime ~= nil and self.nextSoundTime > 0 then
self.nextSoundTime = self.nextSoundTime - dt
if self.nextSoundTime <= 0 then
if self.soundwarn ~= nil then
self.inst.SoundEmitter:PlaySound(self.soundwarn)
end
self.inst:DoTaskInTime(self.warndelay, self.inst.PushEvent, "heargrue")
end
end
if self.nextHitTime ~= nil and self.nextHitTime <= 0 then
self.level = self.level + 1
self.nextHitTime = 5 + math.random() * 6
self.nextSoundTime = self.nextHitTime * (.4 + math.random() * .4)
if self.soundattack ~= nil then
self.inst.SoundEmitter:PlaySound(self.soundattack)
end
if self.level > (self.resistance or 0) then
self.inst.components.combat:GetAttacked(nil, TUNING.GRUEDAMAGE, nil, "darkness")
if self.inst.components.sanity then
self.inst.components.sanity:DoDelta(-TUNING.SANITY_MEDLARGE)
end
self.inst:PushEvent("attackedbygrue")
else
self.inst:PushEvent("resistedgrue")
end
end
end
Adding a check for if the entity being attacked has Sanity to remove Sanity, then if they don't have Sanity the game doesn't crash. I'm sure this would be extremely easy to add & it'd be good for any modders adding AI players (like me) which don't really need Sanity 
.