title: System.Windows.pdb not loaded - Windows Phone
body: <p>I just downloaded the Background worker sample from the website for reference and when i run the application it runs without any problem. The background task is executed normally and toast notifications are shown.</p>
  
  <p>But the problem is after I changed the target version from Windows Phone 7.1 to Windows Phone 8, it didnt execute background tasks. It shows the Error <code>System.Windows.pdb not loaded</code>.</p>
  
  <p>I didnt change the single piece of code in the project. I dontknow why this error occurs.. please help me..</p>
  
  <p>This is the <a href="http://code.msdn.microsoft.com/wpapps/Background-Agent-Sample-02f0087b" rel="nofollow">sample</a> I downloaded from the website.</p>
  
  <p>This is the Call Stack 
  <code>&gt;  System.Windows.ni.dll!MS.Internal.JoltHelper.OnUnhandledException(object sender, System.UnhandledExceptionEventArgs args)   Unknown
          [Native to Managed Transition]<br>
          [Managed to Native Transition]<br>
          mscorlib.ni.dll!System.Reflection.RuntimeAssembly.nLoad(System.Reflection.AssemblyName fileName, string codeBase, System.Security.Policy.Evidence assemblySecurity, System.Reflection.RuntimeAssembly locationHint, ref System.Threading.StackCrawlMark stackMark, System.IntPtr pPrivHostBinder, bool throwOnFileNotFound, bool forIntrospection, bool suppressSecurityChecks) Unknown
      mscorlib.ni.dll!System.Reflection.RuntimeAssembly.InternalLoadAssemblyName(System.Reflection.AssemblyName assemblyRef, System.Security.Policy.Evidence assemblySecurity, System.Reflection.RuntimeAssembly reqAssembly, ref System.Threading.StackCrawlMark stackMark, System.IntPtr pPrivHostBinder, bool throwOnFileNotFound, bool forIntrospection, bool suppressSecurityChecks) Unknown
      mscorlib.ni.dll!System.Reflection.RuntimeAssembly.InternalLoad(string assemblyString, System.Security.Policy.Evidence assemblySecurity, ref System.Threading.StackCrawlMark stackMark, System.IntPtr pPrivHostBinder, bool forIntrospection)    Unknown
      mscorlib.ni.dll!System.Reflection.RuntimeAssembly.InternalLoad(string assemblyString, System.Security.Policy.Evidence assemblySecurity, ref System.Threading.StackCrawlMark stackMark, bool forIntrospection)   Unknown
      mscorlib.ni.dll!System.Reflection.Assembly.Load(string assemblyString)  Unknown
      Microsoft.Phone.ni.dll!Microsoft.Phone.BackgroundAgentActivator.LoadEntryPointAssembly(string assemblyName) Unknown
      Microsoft.Phone.ni.dll!Microsoft.Phone.BackgroundAgentActivator.LoadAgent(string assemblyName, string typeName) Unknown
      Microsoft.Phone.ni.dll!Microsoft.Phone.BackgroundAgentActivator.Microsoft.Phone.IBackgroundAgentActivator.CreateBackgroundAgent(string assembly, string typeinfo)   Unknown
      Microsoft.Phone.ni.dll!Microsoft.Phone.BackgroundAgentDispatcher.AgentRequest.Invoke()  Unknown
      Microsoft.Phone.ni.dll!Microsoft.Phone.BackgroundAgentDispatcher.InvocationThread() Unknown
      mscorlib.ni.dll!System.Threading.ThreadHelper.ThreadStart_Context(object state) Unknown
      mscorlib.ni.dll!System.Threading.ExecutionContext.RunInternal(System.Threading.ExecutionContext executionContext, System.Threading.ContextCallback callback, object state, bool preserveSyncCtx)    Unknown
      mscorlib.ni.dll!System.Threading.ExecutionContext.Run(System.Threading.ExecutionContext executionContext, System.Threading.ContextCallback callback, object state, bool preserveSyncCtx)    Unknown
      mscorlib.ni.dll!System.Threading.ExecutionContext.Run(System.Threading.ExecutionContext executionContext, System.Threading.ContextCallback callback, object state)  Unknown
      mscorlib.ni.dll!System.Threading.ThreadHelper.ThreadStart() Unknown
      [Native to Managed Transition]
  </code></p>