Rowindexoutofrange in SSIS component

See more:

C#

SSIS

Hi, I have a SSIS 2016 package in which I have Script Component in Data Flow. In the script component I have C# codes to process all the incoming data and finally insert them into database.
When I execute the package, it throws me an error as title above. I put a breakpoint at the very beginning of the codes and found the error above.
Below are my codes:

public override void Input0_ProcessInput(Input0Buffer Buffer) 
    {//breakpoint here
        base.Input0_ProcessInput(Buffer);
        try
        {
            //loop through each row
            while (Buffer.NextRow())
            {
                Input0_ProcessInputRow(Buffer);//put all data into DataTable
            }

            //when done collecting all rows, do calculations
            if (Buffer.EndOfRowset())
            {
                 //extra codes here
            }
        }
        catch(Exception ex){}
    }

When I mouseover the "Buffer", it already has the error.

What I have tried:

1. Try to assign MappedColumnId to each of the input columns but error still persist.
2. Check online for solution. Microsoft do suggest to out Buffer.NextRow() checking in which I already have at the first place.