C# [SOLVED] Why am I getting an IndexOutOfRange Error

Programming languages
#1

[SOLVED] - Bloody incremented the wrong variable.

My code is spitting out and IndexOutOfRange Error, yet it manages to print each element to the console perfectly fine.
I can’t for the life of me work out where my bug is.
Please help, I’m questioning life choices at this point.

Error:
Unhandled Exception: System.IndexOutOfRangeException: Index was outside the bounds of the array.

The line of code I get the error:
for (x = 0; x < BOARDLENGTH && Board[x, y] != otherPlayer; y++)

The code block:

        for (int y = 0; y < BOARDLENGTH; y++)
        {
            count = 0;
            nextSpace = new int[] { -1, -1 };
            int x = 0;

            Console.Error.WriteLine(x < BOARDLENGTH && Board[x, y] != otherPlayer);
            for (x = 0; x < BOARDLENGTH && Board[x, y] != otherPlayer; y++)
            {
                if (Board[x, y] == playerToCheck)
                    count++;
                else
                    nextSpace = new int[] { x, y };
            }

            if (count >= 2)
                return nextSpace;
        }

Output Stream:
True