Query combination of filter and nested queries fails with "Accept version must be either version 8 or 7, but found 9. Accept=application/vnd.elasticsearch+json;compatible-with=9"

[tudordumitriu]

Elastic.Clients.Elasticsearch version**: 9.0.1

Elasticsearch version: 8.16.0

.NET runtime version: 8.0.15

Operating system version: Windows 11
Description of the problem including expected versus actual behavior:
When trying to execute a query a little more complex we are getting
"Accept version must be either version 8 or 7, but found 9. Accept=application/vnd.elasticsearch+json;compatible-with=9"
If we try to execute it directly via Postman by taking from debug the request all works fine

Steps to reproduce:

1. Build complex query
2. Execute it against Elastic Search 8.16.0

Expected behavior
Successful execution of the query

Provide ConnectionSettings (if relevant):

Provide DebugInformation (if relevant):

[tudordumitriu]

Update:
The filter is actually a GeoDistanceQuery that we couldn't execute against a geo_point text because it was throwing various other errors in Elastic.Clients.Elasticsearch 8.x like "Unable to locate factory for multi-item union accepting a string value." so we decided to upgrade
We tried using DisableMetaHeader or setting GlobalHeaders to an empty collection but nothing worked

[flobernd]

Hi @tudordumitriu ,

I should probably add 9.x to the compatibility matrix. The client uses a "server versioning" schema. This means that all 9.x client versions are not backwards compatible with 8.x clusters. You must use a 8.x client version when speaking to a 8.x cluster. The 8.x client however can talk to 9.x server (it's always forward compatible for 1 major version).

FYI: I have decided to backport all the improvements of 9.0 to the upcoming 8.19 release of the client.

Check this issue for a workaround (not recommended; not officially supported; no support will be provided in case of problems):
#8501