构建CosmosDB触发的Azure函数时遇到错误

Question

我试图检查我的azure函数（CosmosDB触发器）是否可以查看CosmosDB数据库中的文档，当我在Visual Studio中构建项目时遇到此错误。

[26-11-2018 12:08:51] Host started (33917ms)
[26-11-2018 12:08:51] Job host started
[26-11-2018 12:08:51] The following 1 functions are in error:
[26-11-2018 12:08:51] Function1: The listener for function 'Function1' was unable to start. Microsoft.Azure.Documents.Client: Service is currently unavailable.
[26-11-2018 12:08:51] Microsoft.Azure.Documents.Client: The requested resource is no longer available at the server.

[26-11-2018 12:08:53] Retrying to start listener for function 'Function1' (Attempt 1)
[26-11-2018 12:08:53] A ScriptHost error has occurred
[26-11-2018 12:08:53] The listener for function 'Function1' was unable to start. Microsoft.Azure.Documents.ChangeFeedProcessor: Object reference not set to an instance of an object.

我已经多次重启PC和Visual Studio，并且还更新了Visual Studio，我再次检查了连接字符串，但仍然遇到相同的错误。有人知道这意味着什么吗？哪里有问题？

我拥有的代码是Azure功能的标准代码：

    public static class Function1
{
    [FunctionName("Function1")]
    public static void Run([CosmosDBTrigger(
        databaseName: "cosmostest",
        collectionName: "Items",
        ConnectionStringSetting = "DBConnection",
        LeaseCollectionName = "leases")]IReadOnlyList<Document> documents, TraceWriter log)
    {
        if (documents != null && documents.Count > 0)
        {
            log.Verbose("Documents modified " + documents.Count);
            log.Verbose("First document Id " + documents[0].Id);
        }
    }
}