title: ICloudStorageAccessToken Open says Null reference
body: <p>I have a problem of opening a dropbox folder.  It a code that generates an exe. Basically when the exe is executed, it starts to download a package stored in a dropbox folder. Here is my code: </p>
  
  <pre><code>    _storage = new CloudStorage();
  
      var dropBoxCredentials = new DropBoxCredentials();
  
      dropBoxCredentials.ConsumerKey = "xxxxxxxxxxxxxxx";
      dropBoxCredentials.ConsumerSecret = "xxxxxxxxxxxxxxx";
  
      dropBoxCredentials.UserName = "someusername";
      dropBoxCredentials.Password = "somepassword";
  
      DropBoxConfiguration configuration = DropBoxConfiguration.GetStandardConfiguration();
  
      //open the dropbox connection
      _storage.Open(configuration, dropBoxCredentials);
  </code></pre>
  
  <p>I am sorry that I have to hide the confidential information, but I assume they are correct. So the problem occurs at <code>_storage.Open(configuration, dropBoxCredentials);</code> It says:
  ![enter image description here][1]</p>
  
  <p>I checked the "<code>configuration</code>" and "<code>dropBoxCredentials</code>", and they are not Null, and so is "<code>_storage</code>". 
  So I am confused, what is the problem here exactly? Thanks a lot.</p>
  
  <p>Edit; Here is the stack trace:</p>
  
  <pre><code>at AppLimit.CloudComputing.SharpBox.StorageProvider.DropBox.DropBoxToken..ctor(OAuthToken token, DropBoxBaseCredentials baseCreds)
  at AppLimit.CloudComputing.SharpBox.StorageProvider.DropBox.Logic.DropBoxStorageProviderService.AuthorizeAndGetSession(DropBoxCredentials credentials, DropBoxConfiguration configuration)
  at AppLimit.CloudComputing.SharpBox.StorageProvider.DropBox.Logic.DropBoxStorageProviderService.Authorize(DropBoxCredentials credentials, DropBoxConfiguration configuration)
  at AppLimit.CloudComputing.SharpBox.StorageProvider.DropBox.Logic.DropBoxStorageProviderService.CreateSession(ICloudStorageCredentials credentials, ICloudStorageConfiguration configuration)
  at AppLimit.CloudComputing.SharpBox.StorageProvider.GenericStorageProvider.Open(ICloudStorageConfiguration configuration, ICloudStorageCredentials credentials)
  at AppLimit.CloudComputing.SharpBox.CloudStorage.Open(ICloudStorageConfiguration configuration, ICloudStorageCredentials credentials)
  at WebUpdater.Program.Main(String[] args) in C:\\TIS\\Tools\\WebUpdater\\WebUpdater\\Program.cs:line 52
  at System.AppDomain._nExecuteAssembly(Assembly assembly, String[] args)
  at System.AppDomain.ExecuteAssembly(String assemblyFile, Evidence assemblySecurity, String[] args)
  at Microsoft.VisualStudio.HostingProcess.HostProc.RunUsersAssembly()
  at System.Threading.ThreadHelper.ThreadStart_Context(Object state)
  at System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state)
  at System.Threading.ThreadHelper.ThreadStart()
  </code></pre>