hediffs fail to tick completely after a while

[Voker57]

Often, all pawns stop taking damage and resume only after loading the game.

This is spammed for all the pawns fighting:

Exception ticking hediff (Gunshot shell ticksSinceCreation=5) for pawn Megaspider2200499. Removing hediff... Exception: System.NullReferenceException: Object reference not set to an instance of an object
  at Verse.HediffComp.CompPostTick (System.Single& severityAdjustment) <0x426d1ea0 + 0x00000> in <8ab778f913ea4941b17d6942d15c2508>:0 
  at (wrapper dynamic-method) Verse.HediffComp_SeverityPerDay.Verse.HediffComp_SeverityPerDay.CompPostTick_Patch0(Verse.HediffComp_SeverityPerDay,single&)
  at (wrapper dynamic-method) Verse.HediffComp_TendDuration.Verse.HediffComp_TendDuration.CompPostTick_Patch1(Verse.HediffComp_TendDuration,single&)
  at Verse.HediffWithComps.PostTick () [0x00024] in <8ab778f913ea4941b17d6942d15c2508>:0 
  at (wrapper dynamic-method) Verse.Pawn_HealthTracker.Verse.Pawn_HealthTracker.HealthTick_Patch1(Verse.Pawn_HealthTracker)
Verse.Log:Verse.Log.Error_Patch1(String, Boolean)
Verse.Pawn_HealthTracker:Verse.Pawn_HealthTracker.HealthTick_Patch1(Pawn_HealthTracker)
Verse.Pawn:Verse.Pawn.Tick_Patch3(Pawn)
Verse.TickList:Tick()
Verse.TickManager:Verse.TickManager.DoSingleTick_Patch1(TickManager)
Verse.TickManager:TickManagerUpdate()
Verse.Game:UpdatePlay()
Verse.Root_Play:Update()

[zakhad]

Still a problem?