"Column out of Range" Error when populating an Excel Sheet

As per the elaboration by @Darren Young Excel uses 1 based indexing thats where the issue is.

  using OfficeOpenXml;

    //..
    ExcelWorksheet VerificationSheet_Sheet4 = package.Workbook.Worksheets.Add("SheetTitleHere");
    int row = 1, col = 1;
    VerificationSheet_Sheet4.Cells[row + 1, col].Value = "AnyStringHere"; 

Excel worksheets use 1 based indexing rather than zero based. Thus columns and rows both start at 1 and not 0.