title: How to resolve the Method not found in C#?
body: <p>I'm trying to read an xlsx file, and I got a basic overview from <a href="https://www.codeproject.com/Tips/801032/Csharp-How-To-Read-xlsx-Excel-File-With-Lines-Of-C" rel="nofollow noreferrer">This Codeproject Link</a>
  <br>
  Now, I'm getting the following exception message: <br>
  <a href="https://i.stack.imgur.com/1d1e3.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/1d1e3.png" alt="Exception Message"></a>
  <br>
  The code segment related to this exception is given below:<br></p>
  
  <pre><code>public static sst SharedStrings;
  
      /// &lt;summary&gt;
      /// All worksheets in the Excel workbook deserialized
      /// &lt;/summary&gt;
      /// &lt;param name="ExcelFileName"&gt;Full path and filename of the Excel xlsx-file&lt;/param&gt;
      /// &lt;returns&gt;&lt;/returns&gt;
      public static IEnumerable&lt;worksheet&gt; Worksheets(string ExcelFileName)
      {
          worksheet ws;
          using (ZipArchive zipArchive = ZipFile.Open(ExcelFileName, ZipArchiveMode.Read))
          {
              SharedStrings = DeserializedZipEntry&lt;sst&gt;(GetZipArchiveEntry(zipArchive, @"xl/sharedStrings.xml"));
              foreach (var worksheetEntry in (WorkSheetFileNames(zipArchive)).OrderBy(x =&gt; x.FullName))
              {
                  ws = DeserializedZipEntry&lt;worksheet&gt;(worksheetEntry);
                  ws.NumberOfColumns = worksheet.MaxColumnIndex + 1;
                  ws.ExpandRows();
                  yield return ws;
              }
          }
      }
  </code></pre>
  
  <p><br>
  After some searching, I figured out that I needed to target .NET 4.5 or above version, (I'm targetting 4.6.1, but I also have tried 4.5, still same results). Also, as far as the dependencies are concerned, my references look like this:<br>
  <a href="https://i.stack.imgur.com/1ipYc.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/1ipYc.png" alt="References Image"></a>
  <br>
  After doing all this, I'm still getting the exception mentioned above, and have no idea why this is happening.
  <br>
  EDIT 1: I've been through <a href="https://stackoverflow.com/questions/8058832/system-missingmethodexception-method-not-found">This StackOverflow Link</a>, where I figured that I need the latest DLLs. I went to the Nuget Package Manager, and there were "No Packages Found" which were available for the updates.</p>