title: Windows Phone 7 : FileStream exception
body: <p>I try to use FileStream (using namespace System.IO) but I get an exception :</p>
  
  <pre><code>Attempt to access the method failed 
  </code></pre>
  
  <p>Here is the code :</p>
  
  <pre><code>FileStream fs = new FileStream("file.txt", FileMode.Create); 
  </code></pre>
  
  <p>I searched on microsoft.com and I found that this error is because I use a bad library reference.</p>
  
  <p>But in my project, I compile with mscorlib.dll from folder : C:\Program Files (x86)\Reference Assemblies\Microsoft\Framework\Silverlight\v4.0</p>
  
  <p>I need some help, please. </p>