Removing xpack.maps.enabled as advised breaks Kibana

Kibana 7.17

The Kibana Upgrade Assistant is showing me a Critical issue:

Setting "xpack.maps.enabled" is deprecated

Configuring "xpack.maps.enabled" is deprecated and will be removed in 8.0.0.
How to fix

Remove "xpack.maps.enabled" from the Kibana config file, CLI flag, or environment variable (in Docker only) before upgrading to 8.0.0.

kibana.yml currently contains xpack.maps.enabled: false If I remove this, as the Upgrade Assistant is telling me to, then Kibana will not start up. Errors in Kibana log:


[2022-11-17T14:11:39.890+00:00][ERROR][savedobjects-service] [.kibana] Unexpected Elasticsearch ResponseError: statusCode: 500, method: PUT, url: /.kibana/_mapping?timeout=60s error: [mapper_exception]: the [enabled] parameter can't be updated for the object mapping [maps-telemetry],
[2022-11-17T14:11:39.910+00:00][FATAL][root] Error: Unable to complete saved object migrations for the [.kibana] index. Please check the health of your Elasticsearch cluster and try again. Unexpected Elasticsearch ResponseError: statusCode: 500, method: PUT, url: /.kibana_7.17.1_001/_mapping?timeout=60s error: [mapper_exception]: the [enabled] parameter can't be updated for the object mapping [maps-telemetry],
    at migrationStateActionMachine (/usr/share/kibana/src/core/server/saved_objects/migrationsv2/migrations_state_action_machine.js:164:13)
    at processTicksAndRejections (node:internal/process/task_queues:96:5)
    at async Promise.all (index 0)
    at SavedObjectsService.start (/usr/share/kibana/src/core/server/saved_objects/saved_objects_service.js:181:9)
    at Server.start (/usr/share/kibana/src/core/server/server.js:330:31)
    at Root.start (/usr/share/kibana/src/core/server/root/index.js:69:14)
    at bootstrap (/usr/share/kibana/src/core/server/bootstrap.js:120:5)
    at Command.<anonymous> (/usr/share/kibana/src/cli/serve/serve.js:229:5)
[2022-11-17T14:12:41.742+00:00][ERROR][savedobjects-service] [.kibana] Unexpected Elasticsearch ResponseError: statusCode: 500, method: PUT, url: /.kibana_7.17.1_001/_mapping?timeout=60s error: [mapper_exception]: the [enabled] parameter can't be updated for the object mapping [maps-telemetry],
[2022-11-17T14:12:41.775+00:00][FATAL][root] Error: Unable to complete saved object migrations for the [.kibana] index. Please check the health of your Elasticsearch cluster and try again. Unexpected Elasticsearch ResponseError: statusCode: 500, method: PUT, url: /.kibana_7.17.1_001/_mapping?timeout=60s error: [mapper_exception]: the [enabled] parameter can't be updated for the object mapping [maps-telemetry]

Elasticsearch log

[2022-11-17T14:12:41,735][WARN ][r.suppressed             ] [kibana_foo] path: /.kibana-_7.17.1_001/_mapping, params: {index=.kibana_7.17.1_001, timeout=60s}
org.elasticsearch.transport.RemoteTransportException: [master_bar][10.70.13.146:9300][indices:admin/mapping/put]
Caused by: org.elasticsearch.index.mapper.MapperException: the [enabled] parameter can't be updated for the object mapping [maps-telemetry]

The maps-telemetry mapping in the index in question:

$ curl -s "https://$(hostname):9200/.kibana_7.17.1_001/_mapping?pretty" | jq '.[".kibana_7.17.1_001"].mappings.properties."maps-telemetry"' 
{
  "type": "object",
  "dynamic": "false"
}
$

The Elasticsearch cluster health, as queried from the Kibana node, is Green.

Can someone explain what's going wrong and how I can do what the Upgrade Assistant says should be done and still have working Kibana afterwards?

Also, what does/did xpack.maps.enabled do? I can't find a description of it in documentation (even for Kibana 6).

Did you remove it, upgraded your cluster and are you getting this error?

I haven't upgraded the cluster, I've just tried removing the setting. I am not planning to upgrade the cluster any time soon, I'm just slowly going through the Critical issues the Upgrade Assistant says need to be resolved before the upgrade is done.