title: "The specified package is invalid. The main part is missing." In Closed XML
body: <p>I am using the <a href="https://closedxml.codeplex.com/" rel="nofollow">closed XML</a> for generating the excel template. After filling the data in the generated excel, I am trying to import the excel with data. It returns error "The specified package is invalid. The main part is missing." . I am using XLSX file.</p>
  
  <pre><code>try
   {
        var   workbook = new XLWorkbook(FILE_PATH);
  }
  catch (Exception ex)
  {   
           throw;
  }
  </code></pre>
  
  <p>It throws error when creating object of XLWOrkbook using the excel template generated. </p>
  
  <p>Please provide a solution,</p>
  
  <p>Thanks in Advance...</p>