My game keeps crashing!

[ComplexSymbol]

I get this crash message and I don't know how to fix it, can anyone help?

`Unhandled exception. System.NullReferenceException: Object reference not set to an instance of an object.

at ChessChallenge.Chess.Board.MovePiece(Int32 piece, Int32 startSquare, Int32 targetSquare) in /Users/whoami/Downloads/Chess-Challenge-main/Chess-Challenge/src/Framework/Chess/Board/Board.cs:line 113

at ChessChallenge.Chess.Board.MakwhoamieMove(Move move, Boolean inSearch) in /Users/whoami/Downloads/Chess-Challenge-main/Chess-Challenge/src/Framework/Chess/Board/Board.cs:line 142

at ChessChallenge.API.Board.MakeMove(Move move) in /Users/whoami/Downloads/Chess-Challenge-main/Chess-Challenge/src/API/Board.cs:line 83

at MyBot.g__SearchForBestMove|1_0(Board brd, List'1 blacklistedMoves, <>c__DisplayClass1_0& ) in /Users/whoami/Downloads/Chess-Challenge-main/Chess-Challenge/src/My Bot/MyBot.cs:line 57

at MyBot.Think(Board board, Timer timer) in /Users/whoami/Downloads/Chess-Challenge-main/Chess-Challenge/src/My Bot/MyBot.cs:line 86

at ChessChallenge.Application.ChallengeController.GetBotMove() in /Users/whoami/Downloads/Chess-Challenge-main/Chess-Challenge/src/Framework/Application/Core/ChallengeController.cs:line 150

--- End of stack trace from previous location ---
at ChessChallenge.Application.ChallengeController.Update() in /Users/whoami/Downloads/Chess-Challenge-main/Chess-Challenge/src/Framework/Application/Core/ChallengeController.cs:line 378

at ChessChallenge.Application.Program.Main() in /Users/whoami/Downloads/Chess-Challenge-main/Chess-Challenge/src/Framework/Application/Core/Program.cs:line 40`