Indentation doesn't work with } in comment.

[lsahn-gh]

public static void main(string[] args)
{
    int[] c = b[1:3];    // { 4, 6 }
{
    // something 
}

In the code, the last } in comment is automatically worked like a curly bracket right of main block, not like comment. so indentation's been unbalanced as the code above.