Destination array was not long enough. Check destIndex and length, and the array's lower bounds.?

Destination array was not long enough. Check destIndex and length, and the array’s lower bounds <- what is this error???

how can i fix it?
This error occur after i add Array.Copy

i have no idea….

static byte[] sendData = new byte[5];
  static int sendCount = 0;
    
    try
                        {
    
                            Console.Write("->");
                            string text = Console.ReadLine();
                            foreach(string s in text.Split(' '))
                            {
                                if(null != s && "" != s)
                                {
                                    sendData[sendCount++] = Convert.ToByte(s, 16);
                                }
                            }
                            byte[] LRC = new byte[1];
                            LRC = BitConverter.GetBytes((Int16)sendData[2] ^ sendData[3] ^ sendData[4]);
    
                            byte[] hexData = new byte[sendData.Length + LRC.Length];
                            Array.Copy(sendData, 0, hexData, 0, 5);//<-error occur this point
                            Array.Copy(LRC, 0, hexData, hexData.Length + 1, 1);//<-or this point
    
                            port.Write(hexData, 0, hexData.Length);
    
                            Array.Clear(sendData, 0, sendData.Length);
                            Array.Clear(LRC, 0, LRC.Length);
                            Array.Clear(hexData, 0, hexData.Length);
                            sendCount = 0;
                        }
                        catch(Exception e)
                        {
                            Console.WriteLine(e.Message);
                            Console.WriteLine("Check Data");
                        }

>Solution :

Answering on concrete question, the definition of the copy method:

public static void Copy (
    Array sourceArray, int sourceIndex,
    Array destinationArray, int destinationIndex,
    int length);

In your case

Array.Copy(LRC, 0, hexData, hexData.Length + 1, 1);

So, you are trying to copy bytes to array hexData to the index hexData.Length + 1 that is basically out of its boundaries.

I have no idea what you are trying to implement, but you should make sure that destination index during the copy is less or equal than hexData.Length - 1 (also taking into account the length).