title: 'System.Runtime.InteropServices.COMException' in Interop.ZKFPEngXControl.dll (0x80040202)
body: <p>I am developing a winform fingerprint reader application using ZKFinger SDK.<br/>
  When i am running following code: </p>
  
  <pre><code>ZKFPEngXClass obj = new ZKFPEngXClass();
  obj.OnImageReceived += Obj_OnImageReceived;
  obj.OnCapture += Obj_OnCapture;
  obj.OnEnroll += Obj_OnEnroll;
  obj.OnFeatureInfo += Obj_OnFeatureInfo;
  </code></pre>
  
  <p>then i get error on</p>
  
  <pre><code> obj.OnCapture += Obj_OnCapture;
   obj.OnEnroll += Obj_OnEnroll;
   obj.OnFeatureInfo += Obj_OnFeatureInfo;
  </code></pre>
  
  <p>but </p>
  
  <pre><code>obj.OnImageReceived += Obj_OnImageReceived;
  </code></pre>
  
  <p>works fine.</p>
  
  <p>Error is </p>
  
  <blockquote>
    <p>An unhandled exception of type
    'System.Runtime.InteropServices.COMException' occurred in
    Interop.ZKFPEngXControl.dll".<br/> Additional information: Exception
    from HRESULT: 0x80040202</p>
  </blockquote>