Exception ticking RedDragon38726 (at (124, 0, 149)): System.NullReferenceException: Object reference not set to an instance of an object
  at RimWorld.PawnUtility.PawnBlockingPathAt (Verse.IntVec3 c, Verse.Pawn forPawn, System.Boolean actAsIfHadCollideWithPawnsJob, System.Boolean collideOnlyWithStandingPawns, System.Boolean forPathFinder) [0x0003f] in <4e802577611b487897b01fd812711839>:0
  at RimWorld.PawnUtility.AnyPawnBlockingPathAt (Verse.IntVec3 c, Verse.Pawn forPawn, System.Boolean actAsIfHadCollideWithPawnsJob, System.Boolean collideOnlyWithStandingPawns, System.Boolean forPathFinder) [0x00000] in <4e802577611b487897b01fd812711839>:0
  at Verse.AI.Pawn_PathFollower.WillCollideWithPawnAt (Verse.IntVec3 c) [0x0000f] in <4e802577611b487897b01fd812711839>:0
  at Verse.AI.Pawn_PathFollower.PatherTick () [0x0000c] in <4e802577611b487897b01fd812711839>:0
  at (wrapper dynamic-method) Verse.Pawn.DMD<DMD<Tick_Patch1>?-1304838784::Tick_Patch1>(Verse.Pawn)
  at Verse.TickList.Tick () [0x0015c] in <4e802577611b487897b01fd812711839>:0
Verse.Log:Error(String, Boolean)
Verse.TickList:Tick()
Verse.TickManager:DoSingleTick()
Verse.TickManager:TickManagerUpdate()
Verse.Game:UpdatePlay()
Verse.Root_Play:DMD<DMD<Update_Patch1>?-1883351168::Update_Patch1>(Root_Play)

We get this error once we try to hit him.

Exception ticking Bullet_AssaultRifle38759: System.NullReferenceException: Object reference not set to an instance of an object
  at Verse.AI.Pawn_JobTracker.Notify_DamageTaken (Verse.DamageInfo dinfo) [0x00010] in <4e802577611b487897b01fd812711839>:0
  at (wrapper dynamic-method) Verse.Pawn_HealthTracker.DMD<DMD<PreApplyDamage_Patch2>?794752::PreApplyDamage_Patch2>(Verse.Pawn_HealthTracker,Verse.DamageInfo,bool&)
  at Verse.Pawn.PreApplyDamage (Verse.DamageInfo& dinfo, System.Boolean& absorbed) [0x0000d] in <4e802577611b487897b01fd812711839>:0
  at (wrapper dynamic-method) Verse.Thing.DMD<DMD<TakeDamage_Patch1>?309923456::TakeDamage_Patch1>(Verse.Thing,Verse.DamageInfo)
  at RimWorld.Bullet.Impact (Verse.Thing hitThing) [0x0009a] in <4e802577611b487897b01fd812711839>:0
  at Verse.Projectile.ImpactSomething () [0x0014f] in <4e802577611b487897b01fd812711839>:0
  at Verse.Projectile.Tick () [0x000ed] in <4e802577611b487897b01fd812711839>:0
  at Verse.TickList.Tick () [0x0015c] in <4e802577611b487897b01fd812711839>:0
Verse.Log:Error(String, Boolean)
Verse.TickList:Tick()
Verse.TickManager:DoSingleTick()
Verse.TickManager:TickManagerUpdate()
Verse.Game:UpdatePlay()
Verse.Root_Play:DMD<DMD<Update_Patch1>?-1883351168::Update_Patch1>(Root_Play)