title: "Parameter is not valid" exception from System.Drawing.Image.FromStream() method
body: <p>I got a hard time with the Image.FromStream method in my website. The code below works perfect on my computer. But when I uploaded it to the test server, it always gives me "Parameter not valid" exception. </p>
  
  <pre><code>if (!afuImageFile.IsUploading &amp;&amp; afuImageFile.HasFile)
  {
      System.Drawing.Image imgFile = System.Drawing.Image.FromStream(afuImageFile.FileContent);
  }
  </code></pre>
  
  <p>the <code>afuImageFile</code> is an <code>AsynFileUploader</code> control in Ajax Tool Kits. <code>afuImageFile.FileContent</code> is a <code>HttpInputStream</code>. I guess I need to add some permission to some folder. Can anyone help me?</p>