title: when i decrypt base64 string in c# it shows me ????? question mark and some special character sign
body: <p>i have a base64 string and i want to decrypt it thru c# code. but when i apply below code, it shows me question mark and differnt special characters.
  i dont know why it is showing this.</p>
  
  <pre><code>byte[] data = Convert.FromBase64String(encpStr);
  string decodedString = Encoding.UTF8.GetString(data);
  </code></pre>
  
  <p>i created console project in visual studio,   and doing this practice. see my whole code below.</p>
  
  <pre><code>string encStr = "oJe6iooq+PbvArD+C7P7B/cHAAL9Dr2/vvIBFRcVCAYfxxEcygzMFB0eFNEWFC3VKibYLCknMiLeLzU7PC8pOPT19g==";
  
  Console.WriteLine("******************\nEnc String:\n" + encStr + "\n\n\n**********************");
  byte[] data = Convert.FromBase64String(encStr);
  string decStr = Encoding.UTF8.GetString(data);
  Console.WriteLine("\n\n\nDecr String: \n" + decStr + "\n\n");
  Console.ReadKey();
  </code></pre>