13:43:33.751 [pool-2-thread-1] ERROR o.c.o.s.i.job.impl.VariableImportJob - error while writing variables to elasticsearch
org.elasticsearch.action.ActionRequestValidationException: Validation Failed: 1: no requests added;
	at org.elasticsearch.action.ValidateActions.addValidationError(ValidateActions.java:29)
	at org.elasticsearch.action.bulk.BulkRequest.validate(BulkRequest.java:594)
	at org.elasticsearch.action.TransportActionNodeProxy.execute(TransportActionNodeProxy.java:46)
	at org.elasticsearch.client.transport.TransportProxyClient.lambda$execute$0(TransportProxyClient.java:59)
	at org.elasticsearch.client.transport.TransportClientNodesService.execute(TransportClientNodesService.java:251)
	at org.elasticsearch.client.transport.TransportProxyClient.execute(TransportProxyClient.java:59)
	at org.elasticsearch.client.transport.TransportClient.doExecute(TransportClient.java:366)
	at org.elasticsearch.client.support.AbstractClient.execute(AbstractClient.java:408)
	at org.elasticsearch.action.ActionRequestBuilder.execute(ActionRequestBuilder.java:80)
	at org.elasticsearch.action.ActionRequestBuilder.execute(ActionRequestBuilder.java:54)
	at org.elasticsearch.action.ActionRequestBuilder.get(ActionRequestBuilder.java:62)
	at org.camunda.optimize.service.es.writer.VariableWriter.importVariables(VariableWriter.java:95)
	at org.camunda.optimize.service.importing.job.impl.VariableImportJob.executeImport(VariableImportJob.java:21)
	at org.camunda.optimize.service.importing.job.ImportJob.run(ImportJob.java:22)
	at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
	at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
	at java.lang.Thread.run(Thread.java:748)