I started the axis and allies map. I build all my buildings and settlers and warlord, sent diplomats out. I ended the turn, and I think that is when ai controlled things do their thing. I think the keep, which can summon light cavalry and light infantry might have been the reason, but I have no real idea other then when I expected it to happen, I got the error and crash instead. Error code is below. al --------------------------- --------------------------- An error has occurred. Please notify the game creator of this error. You can copy the entire error to your clipboard by pressing control + C. Then you can paste it into an email by pressing control + V and send the email to support@xxxxxxxxxxxxxxxxxxx. System.NullReferenceException: Object reference not set to an instance of an object. at Game.Tile.CanHold(Unit u) in C:\Data\Recent\TacticalRPG\TacticalRPG\Tile.cs:line 110 at Game.HM.IsValidDestination(Tile t, Unit u) in C:\Data\Recent\TacticalRPG\TacticalRPG\HelperMethods.cs:line 557 at Game.AI.<>c__DisplayClass34.<GetNearestSummonableTile>b__31(Tile p) in C:\Data\Recent\TacticalRPG\TacticalRPG\AI.cs:line 365 at Game.BreadthFirstSearch.InnerSearch() in C:\Data\Recent\TacticalRPG\TacticalRPG\BreadthFirstSearch.cs:line 90 at Game.BreadthFirstSearch.Search(Map map, Int32 sourceID, Func`2 isTarget, Func`2 isValid, Func`2 getAdjacentTiles, Int32 depthLimit) in C:\Data\Recent\TacticalRPG\TacticalRPG\BreadthFirstSearch.cs:line 35 at Game.AI.GetNearestSummonableTile(Tile t, Unit curUnit, Skill sk) in C:\Data\Recent\TacticalRPG\TacticalRPG\AI.cs:line 367 at Game.AI.PerformSkills(Unit curUnit, List`1 friends, List`1 enemies) in C:\Data\Recent\TacticalRPG\TacticalRPG\AI.cs:line 242 at Game.AI.RunSimpleAI(Unit u, List`1 friends, List`1 enemies) in C:\Data\Recent\TacticalRPG\TacticalRPG\AI.cs:line 54 at Game.AI.TakeTurn(Func`1 getUnits, Func`1 getFriends, Func`1 getEnemies) in C:\Data\Recent\TacticalRPG\TacticalRPG\AI.cs:line 33 at Game.Battle.Process(Empty ent) in C:\Data\Recent\TacticalRPG\TacticalRPG\States\Battle.cs:line 64 at Game.StateMachine`1.Process() in C:\Data\Recent\TacticalRPG\TacticalRPG\StateMachine.cs:line 38 at Game.Form1.RunGameLoop(Boolean keyPressed) in C:\Data\Recent\TacticalRPG\TacticalRPG\Form1.cs:line 227 at Game.Form1.GameLoopTimer_Tick(Object sender, EventArgs e) in C:\Data\Recent\TacticalRPG\TacticalRPG\Form1.cs:line 179 at System.Windows.Forms.Timer.OnTick(EventArgs e) at System.Windows.Forms.Timer.TimerNativeWindow.WndProc(Message& m) at System.Windows.Forms.NativeWindow.Callback(IntPtr hWnd, Int32 msg, IntPtr wparam, IntPtr lparam) --------------------------- OK --------------------------- "The truth will make you free" Jesus Christ of Nazareth 33AD