通过Salesforce API创建新的定期捐赠时出现问题

Question

最近我遇到了如下所述的错误：

错误：CANNOT_INSERT_UPDATE_ACTIVATE_ENTITY 消息：npe03.RecurringDonations：执行AfterInsert导致：System.NullPointerException：参数1不能为null（npe03）

我用PHP编写，这就是我的数组的样子：

$newRecurring = array();
$newRecurring['Name'] = "Recurring: {$recurring['id']}";
$newRecurring['npe03__Amount__c'] = $recurring['amount'];
$newRecurring['npe03__Date_Established__c'] = date('Y-m-d', strtotime($recurring['date']));
$newRecurring['npe03__Installment_Period__c'] = 'Monthly';
$newRecurring['npe03__Organization__c'] = $account; //I double checked, it is a valid Id

任何人都可以帮助我吗？