title: Zend Soap Server with .NET client - 'unknown error'
body: <p>I have implemented a web service using Zend Soap Server.</p>
  
  <p>Connecting to it using a PHP client (Zend Client) it works as expected. However with a .NET client it is returning the rather unhelpful error 'unknown error'.</p>
  
  <p>Error log is showing:</p>
  
  <pre><code>PHP Notice:  Array to string conversion in /path/to/app/vendor/zendframework/zend-soap/Zend/Soap/Server.php on line 881
  </code></pre>
  
  <p>Has anyone come across this issue? Here is my server code:</p>
  
  <pre><code>public function server()
  {
      // Soap Server options
      $options = array(
          'classmap' =&gt; array(
              'TransactionType' =&gt; 'Acme\TransactionType',
          ),
      );
  
      // Create Soap Server
      $server = new Server(public_path('file.wsdl'), $options);
  
      // Bind Class to Soap Server
      $server-&gt;setClass('Acme\Transaction');
  
      // Handle request
      $server-&gt;handle();
  
  }
  
  public function wsdl()
  {
      // Output WSDL
      $autodiscover = new AutoDiscover(new ArrayOfTypeSequence());
      $autodiscover-&gt;setClass('Acme\Transaction')
                   -&gt;setUri(\URL::route('server'))
                   -&gt;setServiceName('AcmeTransactions');
      $wsdl = $autodiscover-&gt;generate();
  
      $wsdl-&gt;dump(public_path('file.wsdl'));
  }
  </code></pre>
  
  <p>Acme/Transaction looks like this:</p>
  
  <pre><code>class Transaction extends \Eloquent
  {
  
   /**
   * The database table used by the model.
   *
   * @var string
   */
  protected $table = 'transactions';
  
  /**
   * The attributes that aren't mass assignable.
   *
   * @var array
   */
  protected $guarded = array();
  
  /**
   * Saves a TransactionType to the database.
   *
   * @param TransactionType $transaction
   *
   * @return bool
   */
  public static function saveTransaction(TransactionType $transaction)
  {
      /**
       * @var Transaction $model
       */
      $model = new self();
      $model-&gt;fill(
          array(
              'transaction_id'       =&gt; $transaction-&gt;transaction_id,
              'transaction_number'   =&gt; $transaction-&gt;transaction_number,
              // ...
          )
      );
  
      return $model-&gt;save();
  }
  
  }
  </code></pre>
  
  <p>Acme/TransactionType looks like this:</p>
  
  <pre><code>class TransactionType {
  
  /**
   * @var string
   */
  public $transaction_id = '';
  
  /**
   * @var string
   */
  public $transaction_number = '';
  
  // ...
  
  }
  </code></pre>