title: Issue when using variable name in opening PDF (using Spire.Pdf)
body: <p>I need to check a permission ("EditContent") if it is enabled for the PDF on a path or not. I am using Spire.Pdf, when I try to call LoadFromFile with a variable name in argument it throws and error. However, if I am giving a hardcoded value it accepts and do the needful.</p>
  
  <pre><code>using Spire.Pdf;
  
  public void PermissionOfPDF()
  {
      string path = tempPath + fileName + ".pdf";
      PdfDocument pdfDocument = new PdfDocument();
      Console.Write("\n Trying to load the PDF...\n");
      pdfDocument.LoadFromFile(path);
      Console.Write("\n Loaded the PDF...\n");
  }
  </code></pre>
  
  <p>If i use hard coded path instead of pdfDocument.LoadFromFile(path), it opens and check for a particular permission.</p>
  
  <p>I am not sure if would it be due to any coding issue or Spire has this issue.</p>
  
  <p><strong>Any guidance would be greatly appreciated.</strong></p>