# Could not connect to Elasticsearch: Could not create SSL/TLS secure channel

**URL:** <https://discuss.elastic.co/t/could-not-connect-to-elasticsearch-could-not-create-ssl-tls-secure-channel/357877>\
**Category:** Elasticsearch\
**Tags:** language-clients\
**Created:** [April 22, 2024, 2:16am UTC](https://discuss.elastic.co/t/could-not-connect-to-elasticsearch-could-not-create-ssl-tls-secure-channel/357877 "2024-04-22T02:16:31Z")\
**Posts on this page:** 2\
**Page:** 1

<div class="post-metadata">

**Author:** ![hiilmiee](https://avatars.discourse-cdn.com/v4/letter/h/73ab20/32.png) [@hiilmiee](https://discuss.elastic.co/u/hiilmiee)\
**Post date:** [April 22, 2024, 2:16am UTC](https://discuss.elastic.co/t/could-not-connect-to-elasticsearch-could-not-create-ssl-tls-secure-channel/357877/1 "2024-04-22T02:16:31Z")

</div>

Hi Team,  
I am unable to connect to my elasticsearch URL using  
.NET runtime is 4.6.2  
ES .NET client is 8.13.8  
Elasticsearch 8.12.2  
Kibana 8.12.2

The error i got is  
`Invalid Elasticsearch response built from a unsuccessful () low level call on POST: /search-ocr-poc/_search Exception: The request was aborted: Could not create SSL/TLS secure channel. Call: Status code unknown`

here are my code snippets:

```auto
public async Task<ElasticsearchDocs> SearchDocumentsByContent()
{
	var settings = new ElasticsearchClientSettings(new Uri("https://localhost:9200"))
		.CertificateFingerprint("79:5B:70:9A:3A:0F:70:EE:69:F1:23:20:A5:D7:3C:49:C2:46:5A:5D:FC:F4:E1:C1:3A:92:8C:EF:4C:6E:6C:2E")
		.Authentication(new BasicAuthentication("elastic", "password"));

	var client = new ElasticsearchClient(settings);

	var request = new SearchRequest("search-ocr-poc")
	{
		From = 0,
		Size = 100,
		Query = new TermQuery("title") { Value = "All Drafts Documents" }
	};

	var response = await client.SearchAsync<ElasticsearchDocs>(request);
	ElasticsearchDocs esDocs = new ElasticsearchDocs();

	if (response.IsValidResponse)
	{
		esDocs = response.Documents.FirstOrDefault();
	}
	return esDocs;
}

```

i can get result from `https://localhost:9200/search-ocr-poc/_search` and i gotten my CA fingerprints from running this command `openssl x509 -fingerprint -sha256 -in /mnt/c/ElasticSearch/elasticsearch-8.12.2/config/certs/http_ca.crt` and the output is

```auto
sha256 Fingerprint=79:5B:70:9A:3A:0F:70:EE:69:F1:23:20:A5:D7:3C:49:C2:46:5A:5D:FC:F4:E1:C1:3A:92:8C:EF:4C:6E:6C:2E
-----BEGIN CERTIFICATE-----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-----END CERTIFICATE-----

```

i realised .NET 7.x can use NEST but .NET 8.x theres no NEST. whats the different between the 2 ?

Thanks for any assistance

---

<div class="post-metadata">

**Author:** ![flobernd](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/flobernd/32/124877_2.png) [@flobernd](https://discuss.elastic.co/u/flobernd)\
**Post date:** [April 22, 2024, 7:27am UTC](https://discuss.elastic.co/t/could-not-connect-to-elasticsearch-could-not-create-ssl-tls-secure-channel/357877/2 "2024-04-22T07:27:17Z")

</div>

Hi @hiilmiee,

could you please provide the complete call stack of the exception?

> i realised .NET 7.x can use NEST but .NET 8.x theres no NEST. whats the different between the 2 ?

You can use NEST with `net7`, because it targets `netstandard2.0` which is compatible, but I would highly recommend to go for the `Elastic.Clients.Elasticsearch` client. NEST is deprecated and will reach end of life at the end of the year. Besides that, NEST only connects in backwards compatibility mode to Elasticsearch 8 servers, while the new client provides a lot more functionality.