ServerError for DELETE: Type: illegal_argument_exception Reason: "request does not support having a body"

[gianluca-moro]

NEST/Elasticsearch.net Version 7.12.1
Elasticsearch Version 7.12.1
(Note: Worked previously in Version 7.3.2)

When trying to delete a watcher using the following request:

elasticConnection.Client.Watcher.Delete("someWatcherID");

I get the following error:

Elasticsearch.Net.ElasticsearchClientException: The remote server returned an error: (400) Bad Request.. Call: Status code 400 from: DELETE /_watcher/watch/someWatcherID. ServerError: Type: illegal_argument_exception Reason: "request [DELETE /_watcher/watch/someWatcherID] does not support having a body" ---> System.Net.WebException: The remote server returned an error: (400) Bad Request.
   at System.Net.HttpWebRequest.GetResponse()
   at Elasticsearch.Net.HttpWebRequestConnection.Request[TResponse](RequestData requestData)
   --- End of inner exception stack trace ---
   at Elasticsearch.Net.Transport`1.HandleElasticsearchClientException(RequestData data, Exception clientException, IElasticsearchResponse response)
   at Elasticsearch.Net.Transport`1.FinalizeResponse[TResponse](RequestData requestData, IRequestPipeline pipeline, List`1 seenExceptions, TResponse response)
   at Elasticsearch.Net.Transport`1.Request[TResponse](HttpMethod method, String path, PostData data, IRequestParameters requestParameters)
   at Nest.Specification.WatcherApi.WatcherNamespace.Delete(Id id, Func`2 selector)

---

Note that a similar error occurs when trying to delete a document from a standard index (not ".watches").
When calling:

elasticConnection.Client
                .Delete<ElasticWatcher>(watcher.Id, de => de
                                             .Index("watcherdata")
                                             .Refresh(Refresh.True)
                                             );

it also results in the same error:

Elasticsearch.Net.ElasticsearchClientException: The remote server returned an error: (400) Bad Request.. Call: Status code 400 from: DELETE /watcherdata/_doc/77f1ce4d-4d6a-ec2d-42e9-e886a41473b2?refresh=true. ServerError: Type: illegal_argument_exception Reason: "request [DELETE /watcherdata/_doc/77f1ce4d-4d6a-ec2d-42e9-e886a41473b2] does not support having a body" ---> System.Net.WebException: The remote server returned an error: (400) Bad Request.
   at System.Net.HttpWebRequest.GetResponse()
   at Elasticsearch.Net.HttpWebRequestConnection.Request[TResponse](RequestData requestData)
   --- End of inner exception stack trace ---
   at Elasticsearch.Net.Transport`1.HandleElasticsearchClientException(RequestData data, Exception clientException, IElasticsearchResponse response)
   at Elasticsearch.Net.Transport`1.FinalizeResponse[TResponse](RequestData requestData, IRequestPipeline pipeline, List`1 seenExceptions, TResponse response)
   at Elasticsearch.Net.Transport`1.Request[TResponse](HttpMethod method, String path, PostData data, IRequestParameters requestParameters)
   at Nest.ElasticClient.Delete[TDocument](DocumentPath`1 id, Func`2 selector)

---

Note that I can delete the watcher/documents using the low-level client as follows:
elasticConnection.Client.LowLevel.Watcher.Delete<DeleteWatchResponse>("someWatcherID");
This works without problem.
Is intended to only work with the low-level client? Because in version 7.3.2 it worked with the high-level client.

Or alternatively, I can also delete the watcher using a _delete_by_query call on the '.watches' index, but I read that deleting watchers should only be done using the DELETE _watcher/watch/ call.

---

I also created a post on Discuss.Elastic about this issue.

[stevejgordon]

Hi @gianluca-m. Thanks for raising this issue. This indeed looks like a bug due to how the client handles empty request serialisation. Empty requests may include an empty object in the body which the stricter server side handling rejects. I'll pick this up and review the best way forward.

[gianluca-moro]

Hi @stevejgordon
After further investigation, I think that this is probably not a bug with NEST or Elasticsearch.net but rather just a mistake on my end because I forgot to update a package dependency when updating Elasticsearch.net from 7.3.2 to 7.12.1.
After installing all correct dependencies, it is now working as intended.

Sorry for the inconvenience. I will close this issue now.

[kappa7194]

What is the cause of problem and how has it been solved?

We're forced to use version 7.5.1 of the Elasticsearch.Net NuGet package because it's referenced by the third-party application we're extending and we have the same exact problem and I have no idea how to fix it.