Java high level rest client: how to deal with aggregations?

Elastic Stack Elasticsearch
3

I noticed that the aggregation failed when running on a system index.
I changed following:

SearchRequest searchRequest = new SearchRequest()
to
SearchRequest searchRequest = new SearchRequest(index);

Now I added the correct index pattern (see above), but I get another exception now for the aggregation. Query is still running fine:

Exception in thread "main" ElasticsearchStatusException[Elasticsearch exception [type=search_phase_execution_exception, reason=all shards failed]]
	at org.elasticsearch.rest.BytesRestResponse.errorFromXContent(BytesRestResponse.java:177)
	at org.elasticsearch.client.RestHighLevelClient.parseEntity(RestHighLevelClient.java:573)
	at org.elasticsearch.client.RestHighLevelClient.parseResponseException(RestHighLevelClient.java:549)
	at org.elasticsearch.client.RestHighLevelClient.performRequest(RestHighLevelClient.java:456)
	at org.elasticsearch.client.RestHighLevelClient.performRequestAndParseEntity(RestHighLevelClient.java:429)
	at org.elasticsearch.client.RestHighLevelClient.search(RestHighLevelClient.java:368)
	at com.tsystems.elasticsearchclientlts.Test.testAggregation(Test.java:89)
	at com.tsystems.elasticsearchclientlts.Test.main(Test.java:123)
	Suppressed: org.elasticsearch.client.ResponseException: method [GET], host [http://localhost:9999], URI [/tux-*/_search?typed_keys=true&ignore_unavailable=false&expand_wildcards=open&allow_no_indices=true&search_type=query_then_fetch&batched_reduce_size=512], status line [HTTP/1.1 500 Internal Server Error]
{"error":{"root_cause":[{"type":"illegal_state_exception","reason":"value source config is invalid; must have either a field context or a script or marked as unwrapped"}],"type":"search_phase_execution_exception","reason":"all shards failed","phase":"query","grouped":true,"failed_shards":[{"shard":0,"index":"tux-prod-2017.08.12","node":"qaspBNsmRdaXVI8Lq5qj8w","reason":{"type":"illegal_state_exception","reason":"value source config is invalid; must have either a field context or a script or marked as unwrapped"}}]},"status":500}
		at org.elasticsearch.client.RestClient$1.completed(RestClient.java:357)
		at org.elasticsearch.client.RestClient$1.completed(RestClient.java:346)
		at org.apache.http.concurrent.BasicFuture.completed(BasicFuture.java:119)
		at org.apache.http.impl.nio.client.DefaultClientExchangeHandlerImpl.responseCompleted(DefaultClientExchangeHandlerImpl.java:177)
		at org.apache.http.nio.protocol.HttpAsyncRequestExecutor.processResponse(HttpAsyncRequestExecutor.java:436)
		at org.apache.http.nio.protocol.HttpAsyncRequestExecutor.inputReady(HttpAsyncRequestExecutor.java:326)
		at org.apache.http.impl.nio.client.InternalRequestExecutor.inputReady(InternalRequestExecutor.java:83)
		at org.apache.http.impl.nio.DefaultNHttpClientConnection.consumeInput(DefaultNHttpClientConnection.java:265)
		at org.apache.http.impl.nio.client.InternalIODispatch.onInputReady(InternalIODispatch.java:81)
		at org.apache.http.impl.nio.client.InternalIODispatch.onInputReady(InternalIODispatch.java:39)
		at org.apache.http.impl.nio.reactor.AbstractIODispatch.inputReady(AbstractIODispatch.java:114)
		at org.apache.http.impl.nio.reactor.BaseIOReactor.readable(BaseIOReactor.java:162)
		at org.apache.http.impl.nio.reactor.AbstractIOReactor.processEvent(AbstractIOReactor.java:337)
		at org.apache.http.impl.nio.reactor.AbstractIOReactor.processEvents(AbstractIOReactor.java:315)
		at org.apache.http.impl.nio.reactor.AbstractIOReactor.execute(AbstractIOReactor.java:276)
		at org.apache.http.impl.nio.reactor.BaseIOReactor.execute(BaseIOReactor.java:104)
		at org.apache.http.impl.nio.reactor.AbstractMultiworkerIOReactor$Worker.run(AbstractMultiworkerIOReactor.java:588)
		at java.lang.Thread.run(Thread.java:748)