Checker java need help debugging or understanding my issue

import java.util.Scanner;

public class Checkers $\{$

static char blackPieces $=\text{'}$b$\text{'}$;

static char whitePieces $=\text{'}$w$\text{'}$;

static char empty $=\text{'}\text{'}$;

static char blackKing $=\text{'}$B$\text{'}$;

static char whiteKing $=\text{'}$W$\text{'}$;

static String exitCommand $=$ "exit";

static String viewCommand $=$ "view";

private static char$[][]$ board $=$ new char$[8][8]$;

static Scanner scanner $=$ new Scanner$($System$.$in$)$;

private static void initialiseBoard$()\{$

for $($int i $=0$; i $$ board.length; i$++)\{$

for $($int j $=0$; j $$ board$[$i$].$length; j$++)\{$

if $(($i $+$ j$)\%2==1)\{$

if $($i $<mtext\; id="EditorElement\_171835"></mtext><mn\; id="EditorElement\_171836">3</mn><mi\; id="EditorElement\_171837">)</mi><mtext\; id="EditorElement\_171838"></mtext><mi\; id="EditorElement\_171839">\{</mi>$

board$[$i$][$j$]=$ whitePieces;

$\}$ else if $($i $>4)\{$

board$[$i$][$j$]=$ blackPieces;

$\}$ else $\{$

board$[$i$][$j$]=$ empty;

$\}$

$\}$ else $\{$

board$[$i$][$j$]=\text{'}\text{'}$;

$\}$

$\}$

$\}$

$\}$

private static void displayBoard$()\{$

for $($int i $=0$; i $$ board.length; i$++)\{$

System.out.print$("|")$;

for $($int j $=0$; j $$ board$[$i$].$length; j$++)\{$

System.out.print$($board$[$i$][$j$]+"|")$;

$\}$

System.out.println$()$;

$\}$

System.out.println$()$;

System.out.println$()$;

$\}$

private static void startGame$()\{$

int playerTurn $=1$;

while $(!$isGameOver$())\{$

if $($scanner$.$hasNextLine$())\{$

String move $=$ scanner.nextLine$().$trim$().$toLowerCase$()$;

if $($move$.$equalsIgnoreCase$($exitCommand$))\{$

return;

$\}$ else if $($move$.$equalsIgnoreCase$($viewCommand$))\{$

displayBoard$()$;

$\}$ else if $($processMove$($move$))\{$

playerTurn $=($playerTurn $==1)?2$ : $1$; $//$ Switch player turn

$\}$ else $\{$

System.out.println$("$Error$!")$;

$\}$

$\}$

$\}$

$\}$

private static boolean processMove$($String move$)\{$

if $($move$.$equalsIgnoreCase$($viewCommand$))\{$

displayBoard$()$;

return false; $//$ No error for view command

$\}$

String$[]$ positions $=$ move.split$("$ to$")$;

if $($positions$.$length $!=2)\{$

System.out.println$("$Invalid move format."$)$;

return false;

$\}$

String fromPosition $=$ positions$[0].$trim$()$;

String toPosition $=$ positions$[1].$trim$()$;

int fromRow $=$ parseCoordinateRow$($fromPosition$)$;

int fromCol $=$ parseCoordinateCol$($fromPosition$)$;

int toRow $=$ parseCoordinateRow$($toPosition$)$;

int toCol $=$ parseCoordinateCol$($toPosition$)$;

if $(!$isValidMove$($fromRow$,$ fromCol, toRow, toCol$))\{$

System.out.println$("$Invalid move. Please try again."$)$;

return false;

$\}$

board$[$toRow$][$toCol$]=$ board$[$fromRow$][$fromCol$]$;

board$[$fromRow$][$fromCol$]=$ empty;

displayBoard$()$;

return true;

$\}$

private static int parseCoordinateRow$($String coordinate$)\{$

return $8-$ Character.getNumericValue$($coordinate$.$charAt$(1))$;

$\}$

private static int parseCoordinateCol$($String coordinate$)\{$

return coordinate.toLowerCase$().$charAt$(0)-\text{'}$a$\text{'}$;

$\}$

private static boolean isValidMove$($int fromRow, int fromCol, int toRow, int toCol$)\{$

if $($fromRow $<mtext\; id="EditorElement\_174590"></mtext><mn\; id="EditorElement\_174591">0</mn><mtext\; id="EditorElement\_174592"></mtext><mi\; id="EditorElement\_174593">|</mi><mi\; id="EditorElement\_174594">|</mi>$ fromRow $>=$ board.length $||$ fromCol $<mtext\; id="EditorElement\_174632"></mtext><mn\; id="EditorElement\_174633">0</mn><mtext\; id="EditorElement\_174634"></mtext><mi\; id="EditorElement\_174635">|</mi><mi\; id="EditorElement\_174636">|</mi>$ fromCol $>=$ board$[0].$length $||$

toRow $<mtext\; id="EditorElement\_174687"></mtext><mn\; id="EditorElement\_174688">0</mn><mtext\; id="EditorElement\_174689"></mtext><mi\; id="EditorElement\_174690">|</mi><mi\; id="EditorElement\_174691">|</mi>$ toRow $>=$ board.length $||$ toCol $<mtext\; id="EditorElement\_174725"></mtext><mn\; id="EditorElement\_174726">0</mn><mtext\; id="EditorElement\_174727"></mtext><mi\; id="EditorElement\_174728">|</mi><mi\; id="EditorElement\_174729">|</mi>$ toCol $>=$ board$[0].$length$)\{$

return false;

$\}$

if $($board$[$toRow$][$toCol$]!=$ empty$)\{$

return false;

$\}$

int rowDifference $=$ Math.abs$($toRow $-$ fromRow$)$;

int colDifference $=$ Math.abs$($toCol $-$ fromCol$)$;

if $($rowDifference $!=$ colDifference$)\{$

return false;

$\}$

int rowChange $=$ toRow $-$ fromRow;

if $($rowChange

return false;

$\}$

return true;

$\}$

private static boolean isGameOver$()\{$

boolean blackPiecesExist $=$ false;

boolean whitePiecesExist $=$ false;

for $($int i $=0$; i $$ board.length; i$++)\{$

for $($int j $=0$; j $$ board$[$i$].$length; j$++)\{$

if $($board$[$i$][$j$]==$ blackKing $||$ board$[$i$][$j$]==$ blackPieces$)\{$

blackPiecesExist $=$ true;

$\}$ else if $($board$[$i$][$j$]==$ whiteKing $||$ board$[$i$][$j$]==$ whitePieces$)\{$

whitePiecesExist $=$ true;

$\}$

$\}$

$\}$

if $(!$blackPiecesExist$)\{$

System.out.println$("$Player $2$ won"$)$;

return true;

$\}$ else if $(!$whitePiecesExist$)\{$

System.out.println$("$Player $1$ won"$)$;

return true;

$\}$

return false;

$\}$

public static void main$($String$[]$ args$)\{$

initialiseBoard$()$;

displayBoard$()$;

startGame$()$;

$\}$

$\}$current right board output is;