Why is Flash doing array operations wrongly. - arrays

Question

Its was runnning fine and then it through me this error
1125 Error #: 117 index is beyond the scope of 115.
It doesn't list a row number but the function below is the only place where a long array is referred to.
The error means its trying to access between end of the vector array- It shouldn't be possible.
Relevant code parts (the rest-public functions and other functions not include all work fine).
public class Main extends Sprite
{
internal var oneoff:Boolean = true;
internal var kanaList:Vector.<String> = new <String>["あ/ア", "あ/ア", "え/え", "え/え", "い/イ", "い/イ", "お/オ", "お/オ", "う/ウ", "う/ウ", "う/ウ", "う/ウ", "か/カ", "か/カ", "け/ケ", "け/ケ", "き/キ", "き/キ", "く/ク", "く/ク", "こ/コ", "こ/コ", "さ/サ", "さ/サ", "　し/シ", "　し/シ", "す/ス", "す/ス", "そ/ソ", "そ/ソ", "す/ス", "す/ス", "た/タ", "た/タ", "て/テ", "て/テ", "　ち/チ", "　ち/チ", "と/ト", "と/ト", "つ/ツ", "つ/ツ", "ら/ラ", "ら/ラ", "れ/レ", "れ/レ", "り/リ", "り/リ", "ろ/ロ", "ろ/ロ", "る/ル", "る/ル", "だ/ダ", "で/デ", "じ/ジ", "ど／ド", "ず/ズ", "ざ/ザ", "ぜ/ゼ", "ぞ／ゾ", "な/ナ", "ね/ネ", "に/二", "の/ノ", "ぬ/ヌ", "じゃ/ジャ", "じゅ/ジュ", "じょ/ジョ", "ん/ン", "しゃ/シャ", "しゅ/シュ", "しょ/ショ", "や/ヤ", "ゆ/ユ", "よ/ヨ", "は/ハ", "ひ/ヒ", "ふ/フ", "へ/ヘ", "ほ/ホ", "ば/バ", "ば/バ", "ぶ/ブ", "ぶ/ブ", "び/ビ", "び/ビ", "ぼ/ボ", "ぼ/ボ", "べ/ベ", "べ/ベ", "ぱ/パ", "ぴ／ピ", "ぷ/プ", "ぺ/ペ", "ぽ/ポ", "ま/マ", "み/ミ", "　む/ム", "め/メ", "も/モ", "を／ヲ", "みゃ/ミャ", "みゅ/ミャ", "みょ/ミョ", "きゃ/キャ", "きゅ/キュ", "きょ/キョ", "にゃ/ニャ", "にゅ/ニュ", "にょ/ニョ", "びゃ/びゃ", "びゅ/ビュ", "びょ/ビョ", "　　ひゃ/ヒャ", "ひゅ/ヒュ", "ひょ/ヒョ", "ぴゃ/ピャ", "ぴゅ/ピュ", "ぴょ/ピョ", "っ/ッ", "っ/ッ"];
internal var valueList:Vector.<uint>= new <uint>[1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 10, 10, 5, 5, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 20, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 1, 1];
// Lists of Kana that can be replaced in the replace mode and the substitute Kana and Values
internal var selectghostList:Vector.<String>=new<String>["ま/マ","む/ム","も/モ","か/カ","く/ク","こ/コ","な/ナ","ぬ/ヌ","の/ノ","ば/バ","ぶ/ブ","ぼ/ボ","は/ハ","ふ/フ","ほ/ホ","ぱ/パ","ぷ/プ","ぽ/ポ"];
internal var selectkanaList:Vector.<String>=new <String>["みゃ/ミャ", "みゅ/ミャ", "みょ/ミョ", "きゃ/キャ", "きゅ/キュ", "きょ/キョ", "にゃ/ニャ", "にゅ/ニュ", "にょ/ニョ", "びゃ/びゃ", "びゅ/ビュ", "びょ/ビョ", "　　ひゃ/ヒャ", "ひゅ/ヒュ", "ひょ/ヒョ", "ぴゃ/ピャ", "ぴゅ/ピュ", "ぴょ/ピョ"];
internal var selectghostvalueList:Vector.<uint>=new <uint>[2, 2, 3, 3, 3, 3, 3, 3, 3, 2, 2, 2, 2, 2, 2, 2, 2, 2];
//Start list of playerHand contents as I don't know if Null is 0
internal var playernumber:uint;
internal var allplayersHand:Array = [[0], [0], [0], [0],[0], [0]];
internal var playerRound:uint = 1;
internal var round:uint = 1;
internal var aplayersHand:Array;
internal function create():void
{ var listLength:uint;
var row:uint
listLength = kanaList.length;
aplayersHand = allplayersHand[playerRound];
for (var i:uint = (aplayersHand.length); i <= 7; i+=1)
{row = int(Math.random() * listLength); 　
trace (row);
trace(i);
aplayersHand[i] = [0, kanaList[row], valueList[row],]
trace (aplayersHand);
trace (aplayersHand[i]);
kanaList.splice(row,1);
valueList.splice(row,1);
}
deal();
}

Answer 1

I'm assuming it's throwing the error intermittently. The reason I think it's happening is that you stored long array's length in listLength, but didn't decrement its value after
kanaList.splice(row,1);
valueList.splice(row,1);
which is why, I think, row value calculated like
row = int(Math.random() * listLength);
would sometimes return a value which is greater than array's length at that iteration.
On a sidenote, it'd be great to have what all was traced till the point you got the error. Also, the exception should show stack trace, if you compile a debug version of swf and run it in a debug flash player. The stack trace is very very useful to track down bugs like these.