The PHP call $ls->get_question_properties($key,$code) results in

PHP Fatal error:  Uncaught Exception: Request error: Eigenschaft "DefaultValue.defaultvalue ist nicht definiert. in [...]/limesurvey/application/libraries/jsonRPCClient.php:162
Stack trace:
#0 [...]: jsonRPCClient->__call()
#1 [...]
#2 {main}
  thrown in [...]/limesurvey/application/libraries/jsonRPCClient.php on line 162

IMHO this can be fixed by replacing in application/helpers/remotecontrol/remotecontrol_handle.php, function get_question_properties the following part (located at the very end of the function):

                        $aResult['defaultvalue'] = DefaultValue::model()->with('defaultvaluel10ns')
                                                                        ->find(
                                                                            'qid = :qid AND defaultvaluel10ns.language = :language',
                                                                            array(':qid' => $iQuestionID, ':language' => $sLanguage)
                                                                        )
                                                                        ->defaultvalue;

by

                        $aResult['defaultvalue'] = DefaultValue::model()->with('defaultvaluel10ns')
                                                                        ->find(
                                                                            'qid = :qid AND defaultvaluel10ns.language = :language',
                                                                            array(':qid' => $iQuestionID, ':language' => $sLanguage)
                                                                        )
                                                                        ->defaultvaluel10ns[$sLanguage]->defaultvalue;