您可以在保存代码之前加上：

  if （File.Exists（brokenFile））
 {
 File .Delete（brokenFile）; 
} 

After decrypt file, i have a new problem with save change (/silent) Excel files when close workbook, MSExcel always promts to save and replace file in every xlsx file. i really need to Silent,Quiet save quit excel work book. but, I have no idea what i miss?, Help me please, (Sorry for my Language)
Try2SilentSaveExist.rar - File Upload Script[^]

What I have tried:

Microsoft.Office.Interop.Excel.Application MSexcel = new Microsoft.Office.Interop.Excel.Application();
        Microsoft.Office.Interop.Excel.Workbook excelPrj = null;
        /*Microsoft.Office.Interop.Word.Application MSword = new Microsoft.Office.Interop.Word.Application();
        Microsoft.Office.Interop.PowerPoint.Application MSpoint = new Microsoft.Office.Interop.PowerPoint.Application();
        Microsoft.Office.Interop.Access.Application MSAccs = new Microsoft.Office.Interop.Access.Application();
        Microsoft.Office.Interop.Word.Document wordPrj = null;
        Microsoft.Office.Interop.PowerPoint.Presentation pointPrj = null;*/
        Missing miss = Missing.Value;
        private bool RepairFile(string brokenFile)
        {
            if (System.IO.Path.GetExtension(brokenFile).ToLower() == ".xlsx")
            {
                try
                {
                    string OldFile = brokenFile;
                    MSexcel.DisplayAlerts = false;
                    MSexcel.Visible = false;
                    MSexcel.UserControl = false;
                    excelPrj = MSexcel.Workbooks.Open(OldFile, miss, miss, miss, miss, miss, miss, miss, miss, miss, miss, miss, miss, miss, Microsoft.Office.Interop.Excel.XlCorruptLoad.xlRepairFile);
                    if (excelPrj != null)
                    {
                        excelPrj.Close(true);
                    }
                    
                    return true;

                }
                catch { return false; }
            }
            else
            {
                /*
                if (System.IO.Path.GetExtension(brokenFile).ToLower() == ".docx")
                {
                }*/
                return true;
            }
        }

You could precede your saving code with this:

if (File.Exists(brokenFile))
{
    File.Delete(brokenFile); 
}