使用Microsoft Graph创建无提醒日历事件时抛出异常的原因排查

我在使用Microsoft Graph SDK v5创建日历事件时遇到异常，以下代码仅在bSetReminder为false时触发Microsoft.Graph.Models.ODataErrors.ODataError，为true时可正常执行：

// Add the event
Event createdEvent = await _graphClient.Me.Calendars[oSettings.CalendarID].Events.PostAsync(new Event
{
    Subject = oEvent.GetSubject(),
    Body = body,
    Start = startTime,
    End = endTime,
    IsAllDay = oEvent.IsAllDayEvent(),
    IsReminderOn = bSetReminder,
    ReminderMinutesBeforeStart = bSetReminder ? iReminderMinutes : (int?)null,
    Location = location,
    SingleValueExtendedProperties = extendedProperties,
    Sensitivity = oSettings.SetCalendarPrivate ? Sensitivity.Private : Sensitivity.Normal
});

经排查，问题出在这行代码：

ReminderMinutesBeforeStart = bSetReminder ? iReminderMinutes : (int?)null

我尝试捕获异常但未获取到有效细节：

catch (Microsoft.Graph.Models.ODataErrors.ODataError ex)
{
    SimpleLog.Log(ex);
    SimpleLog.Log(ex.InnerException);
    return false;
}

将代码修改为以下形式后可正常运行：

ReminderMinutesBeforeStart = bSetReminder ? iReminderMinutes : 0

查看SDK v5中ReminderMinutesBeforeStart的属性定义仍为int?类型，无法理解为何传入(int?)null会引发异常，需要具体的原因解释。

内容的提问来源于stack exchange，提问作者Andrew Truckle