Index was outside the bounds of the array.

public class K1
{
    public K1()
    {
        I1Value = new I1[] {  };
    }

    private I1[] I1Value;

    public I1[] K1_Method
    {
        get
        {
            return this.I1Value;
        }
        set
        {
            this.I1Value = value;
        }
    }
}
public class I1
{
    public I1()
    {
        Cd = new InstCode();
    }
    private InstCode cdField;

    private string instField;

    public InstCode Cd
    {
        get
        {
            return this.cdField;
        }
        set
        {
            this.cdField = value;
        }
    }
    public string InstrInf
    {
        get
        {
            return this.instField;
        }
        set
        {
            this.instField = value;
        }
    }
}

public enum InstCode
{
    A,
    B,
    C,
    D,