(!) Exception: Program.CurrentDomain_UnhandledException

Object reference not set to an instance of an object.
Version = 1.30.13172 develop/commit
Mod = Combined Arms
ModVersion = 7.6F
StarDate = 1190.6
Ships = 2278
Planets = 472
Memory = 299319
XnaMemory = 293939
Thread = Universe.SimThread
ThreadId = 32
Thread #32 Universe.SimThread StackTrace:
   at Fleets.Fleet.EndInvalidTask(Boolean condition) in Fleets\Fleet.cs:line 1605
   at Fleets.Fleet.DoAssaultPlanet(MilitaryTask task) in Fleets\Fleet.cs:line 982
   at Fleets.Fleet.EvaluateTask(FixedSimTime timeStep) in Fleets\Fleet.cs:line 614
   at Fleets.Fleet.UpdateAI(FixedSimTime timeStep, Int32 which) in Fleets\Fleet.cs:line 2237
   at Empire.UpdateFleets(FixedSimTime timeStep) in Empire.cs:line 1863
   at Empire.Update(FixedSimTime timeStep) in Empire.cs:line 1606
   at UniverseScreen.UpdateEmpires(FixedSimTime timeStep) in Universe\UniverseScreen\UniverseScreen.UpdateGame.cs:line 427
   at UniverseScreen.ProcessTurnEmpires(FixedSimTime timeStep) in Universe\UniverseScreen\UniverseScreen.UpdateGame.cs:line 379
   at UniverseScreen.SingleSimulationStep(FixedSimTime timeStep) in Universe\UniverseScreen\UniverseScreen.UpdateGame.cs:line 203
   at UniverseScreen.ProcessSimulationTurns() in Universe\UniverseScreen\UniverseScreen.UpdateGame.cs:line 160
   at UniverseScreen.UniverseSimulationLoop() in Universe\UniverseScreen\UniverseScreen.UpdateGame.cs:line 88
   at UniverseScreen.UniverseSimMonitored() in Universe\UniverseScreen\UniverseScreen.UpdateGame.cs:line 58
   at System.Threading.ThreadHelper.ThreadStart_Context(Object state)
   at System.Threading.ExecutionContext.RunInternal(ExecutionContext executionContext, ContextCallback callback, Object state, Boolean preserveSyncCtx)
   at System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state, Boolean preserveSyncCtx)
   at System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state)
   at System.Threading.ThreadHelper.ThreadStart()

Thread #1 Main Thread StackTrace:
   at XNA.WindowsGameHost.Run() in ts\BlackBox\XNA.Game\WindowsGameHost.cs:line 93
   at XNA.Game.Run() in ts\BlackBox\XNA.Game\Game.cs:line 166
   at Program.Main(String[] args) in GameScreens\Program.cs:line 166