Exception ticking Squirrel20124: System.NullReferenceException: Object reference not set to an instance of an object
  at Verse.AI.RegionCostCalculator.GetRegionDistance (Verse.Region region, Verse.RegionLink& minLink) [0x000ea] in C:\Dev\RimWorld\Assets\Scripts\Verse\AI\Pathing\RegionCostCalculator.cs:184
  at Verse.AI.RegionCostCalculator.GetRegionBestDistances (Verse.Region region, Verse.RegionLink& bestLink, Verse.RegionLink& secondBestLink, System.Int32& secondBestCost) [0x00000] in C:\Dev\RimWorld\Assets\Scripts\Verse\AI\Pathing\RegionCostCalculator.cs:226
  at Verse.AI.RegionCostCalculatorWrapper.GetPathCostToRegion (Int32 cellIndex) [0x0004c] in C:\Dev\RimWorld\Assets\Scripts\Verse\AI\Pathing\RegionCostCalculatorWrapper.cs:118
  at Verse.AI.PathFinder.FindPath (IntVec3 start, LocalTargetInfo dest, TraverseParms traverseParms, PathEndMode peMode) [0x00c85] in C:\Dev\RimWorld\Assets\Scripts\Verse\AI\Pathing\PathFinder.cs:551
  at Verse.AI.PathFinder.FindPath (IntVec3 start, LocalTargetInfo dest, Verse.Pawn pawn, PathEndMode peMode) [0x00025] in C:\Dev\RimWorld\Assets\Scripts\Verse\AI\Pathing\PathFinder.cs:103
  at Verse.AI.Pawn_PathFollower.GenerateNewPath () [0x00011] in C:\Dev\RimWorld\Assets\Scripts\Verse\AI\Pathing\Pawn_PathFollower.cs:630
  at Verse.AI.Pawn_PathFollower.TrySetNewPath () [0x00000] in C:\Dev\RimWorld\Assets\Scripts\Verse\AI\Pathing\Pawn_PathFollower.cs:583
  at Verse.AI.Pawn_PathFollower.TryEnterNextPathCell () [0x00215] in C:\Dev\RimWorld\Assets\Scripts\Verse\AI\Pathing\Pawn_PathFollower.cs:487
  at Verse.AI.Pawn_PathFollower.PatherTick () [0x001ed] in C:\Dev\RimWorld\Assets\Scripts\Verse\AI\Pathing\Pawn_PathFollower.cs:255
  at Verse.Pawn.Tick () [0x0004e] in C:\Dev\RimWorld\Assets\Scripts\Verse\Pawn\Pawn.cs:470
  at Verse.TickList.Tick () [0x0018f] in C:\Dev\RimWorld\Assets\Scripts\Verse\Game\Ticking\TickList.cs:126
Verse.Log:Error(String) (at C:\Dev\RimWorld\Assets\Scripts\Verse\Utility\Debug\Log\Log.cs:48)
Verse.TickList:Tick() (at C:\Dev\RimWorld\Assets\Scripts\Verse\Game\Ticking\TickList.cs:137)
Verse.TickManager:DoSingleTick() (at C:\Dev\RimWorld\Assets\Scripts\Verse\Game\Ticking\TickManager.cs:276)
Verse.TickManager:TickManagerUpdate() (at C:\Dev\RimWorld\Assets\Scripts\Verse\Game\Ticking\TickManager.cs:243)
Verse.Game:UpdatePlay() (at C:\Dev\RimWorld\Assets\Scripts\Verse\Game\Game.cs:481)
Verse.Root_Play:Update() (at C:\Dev\RimWorld\Assets\Scripts\Verse\Global\Root\Root_Play.cs:73)

Loading game from file XA1 with mods Core, AlienRaceA17, XennRaceA17, XA17, XenDrill17, XRMinerals17, XenLeafA17, and Star-Wars---Factionsa17
Verse.Log:Message(String) (at C:\Dev\RimWorld\Assets\Scripts\Verse\Utility\Debug\Log\Log.cs:30)
Verse.SavedGameLoader:LoadGameFromSaveFile(String) (at C:\Dev\RimWorld\Assets\Scripts\Verse\Map\MapIniter\SavedGameLoader.cs:17)
Verse.Root_Play:<Start>m__853() (at C:\Dev\RimWorld\Assets\Scripts\Verse\Global\Root\Root_Play.cs:29)
Verse.LongEventHandler:RunEventFromAnotherThread(Action) (at C:\Dev\RimWorld\Assets\Scripts\Verse\Global\LongEventHandler.cs:439)
Verse.LongEventHandler:<UpdateCurrentAsynchronousEvent>m__850() (at C:\Dev\RimWorld\Assets\Scripts\Verse\Global\LongEventHandler.cs:353)

--- Thread 9 ---
 25665ms Loading game from file XA1
 - 276ms InitLoading (read file)
 - 0ms Load compressed things
 - 2951ms Load non-compressed things
 - 155ms FinalizeLoading
 - - 0ms Load compressed things
 - - 0ms Load non-compressed things
 - - 0ms Load compressed things
 - - 0ms Load non-compressed things
 - 0ms Merge compressed and non-compressed thing lists
 - 238ms Spawn everything into the map

Verse.Log:Message(String) (at C:\Dev\RimWorld\Assets\Scripts\Verse\Utility\Debug\Log\Log.cs:30)
Verse.ThreadLocalDeepProfiler:Output(Watcher) (at C:\Dev\RimWorld\Assets\Scripts\Verse\Utility\Debug\DeepProfiler\DeepProfiler.cs:147)
Verse.ThreadLocalDeepProfiler:End() (at C:\Dev\RimWorld\Assets\Scripts\Verse\Utility\Debug\DeepProfiler\DeepProfiler.cs:133)
Verse.DeepProfiler:End() (at C:\Dev\RimWorld\Assets\Scripts\Verse\Utility\Debug\DeepProfiler\DeepProfiler.cs:52)
Verse.SavedGameLoader:LoadGameFromSaveFile(String) (at C:\Dev\RimWorld\Assets\Scripts\Verse\Map\MapIniter\SavedGameLoader.cs:47)
Verse.Root_Play:<Start>m__853() (at C:\Dev\RimWorld\Assets\Scripts\Verse\Global\Root\Root_Play.cs:29)
Verse.LongEventHandler:RunEventFromAnotherThread(Action) (at C:\Dev\RimWorld\Assets\Scripts\Verse\Global\LongEventHandler.cs:439)
Verse.LongEventHandler:<UpdateCurrentAsynchronousEvent>m__850() (at C:\Dev\RimWorld\Assets\Scripts\Verse\Global\LongEventHandler.cs:353)

Exception ticking PlantGrass14755: System.NullReferenceException: Object reference not set to an instance of an object
  at Verse.RegionAndRoomUpdater.NotifyAffectedRoomsAndRoomGroupsAndUpdateTemperature () [0x0014c] in C:\Dev\RimWorld\Assets\Scripts\Verse\Map\RegionsAndRooms\RegionAndRoomUpdater.cs:431
  at Verse.RegionAndRoomUpdater.CreateOrUpdateRooms () [0x000a4] in C:\Dev\RimWorld\Assets\Scripts\Verse\Map\RegionsAndRooms\RegionAndRoomUpdater.cs:176
  at Verse.RegionAndRoomUpdater.TryRebuildDirtyRegionsAndRooms () [0x00075] in C:\Dev\RimWorld\Assets\Scripts\Verse\Map\RegionsAndRooms\RegionAndRoomUpdater.cs:83
  at Verse.RegionGrid.GetValidRegionAt (IntVec3 c) [0x0006c] in C:\Dev\RimWorld\Assets\Scripts\Verse\Map\RegionsAndRooms\RegionGrid.cs:122
  at Verse.RegionAndRoomQuery.RegionAt (IntVec3 c, Verse.Map map, RegionType allowedRegionTypes) [0x0000e] in C:\Dev\RimWorld\Assets\Scripts\Verse\Map\RegionsAndRooms\RegionAndRoomQuery.cs:20
  at Verse.RegionAndRoomQuery.RoomAt (IntVec3 c, Verse.Map map, RegionType allowedRegionTypes) [0x00000] in C:\Dev\RimWorld\Assets\Scripts\Verse\Map\RegionsAndRooms\RegionAndRoomQuery.cs:42
  at Verse.RegionAndRoomQuery.RoomGroupAt (IntVec3 c, Verse.Map map) [0x00000] in C:\Dev\RimWorld\Assets\Scripts\Verse\Map\RegionsAndRooms\RegionAndRoomQuery.cs:48
  at Verse.GridsUtility.GetRoomGroup (IntVec3 loc, Verse.Map map) [0x00000] in C:\Dev\RimWorld\Assets\Scripts\Verse\Map\Grids\GridsUtility.cs:28
  at Verse.GenTemperature.TryGetDirectAirTemperatureForCell (IntVec3 c, Verse.Map map, System.Single& temperature) [0x00015] in C:\Dev\RimWorld\Assets\Scripts\Verse\Map\Temperature\GenTemperature.cs:115
  at Verse.GenTemperature.TryGetTemperatureForCell (IntVec3 c, Verse.Map map, System.Single& tempResult) [0x0002e] in C:\Dev\RimWorld\Assets\Scripts\Verse\Map\Temperature\GenTemperature.cs:83
  at Verse.GenTemperature.GetTemperatureForCell (IntVec3 c, Verse.Map map) [0x00000] in C:\Dev\RimWorld\Assets\Scripts\Verse\Map\Temperature\GenTemperature.cs:61
  at Verse.Thing.get_AmbientTemperature () [0x0002a] in C:\Dev\RimWorld\Assets\Scripts\Verse\Thing\Thing.cs:357
  at RimWorld.Plant.CheckTemperatureMakeLeafless () [0x00000] in C:\Dev\RimWorld\Assets\Scripts\RimWorld\Thing\Plant\Plant.cs:355
  at RimWorld.Plant.TickLong () [0x00000] in C:\Dev\RimWorld\Assets\Scripts\RimWorld\Thing\Plant\Plant.cs:383
  at Verse.TickList.Tick () [0x001b5] in C:\Dev\RimWorld\Assets\Scripts\Verse\Game\Ticking\TickList.cs:128
Verse.Log:Error(String) (at C:\Dev\RimWorld\Assets\Scripts\Verse\Utility\Debug\Log\Log.cs:48)
Verse.TickList:Tick() (at C:\Dev\RimWorld\Assets\Scripts\Verse\Game\Ticking\TickList.cs:137)
Verse.TickManager:DoSingleTick() (at C:\Dev\RimWorld\Assets\Scripts\Verse\Game\Ticking\TickManager.cs:284)
Verse.TickManager:TickManagerUpdate() (at C:\Dev\RimWorld\Assets\Scripts\Verse\Game\Ticking\TickManager.cs:243)
Verse.Game:UpdatePlay() (at C:\Dev\RimWorld\Assets\Scripts\Verse\Game\Game.cs:481)
Verse.Root_Play:Update() (at C:\Dev\RimWorld\Assets\Scripts\Verse\Global\Root\Root_Play.cs:73)