Neo4j shell import issue
I have an issue with Neo4j shell import. I'm loading data for an initial import to the database. I use about 70 files that contains nodes and relation for the import. But I get an error
Import error: Nodes for any specific group must be added in sequence before adding nodes for any other group
java.lang.IllegalStateException: Nodes for any specific group must be added in sequence before adding nodes for any other group
at org.neo4j.unsafe.impl.batchimport.cache.idmapping.string.EncodingIdMapper.put(EncodingIdMapper.java:199)
at org.neo4j.unsafe.impl.batchimport.NodeEncoderStep.process(NodeEncoderStep.java:77)
at org.neo4j.unsafe.impl.batchimport.NodeEncoderStep.process(NodeEncoderStep.java:43)
at org.neo4j.unsafe.impl.batchimport.staging.ProcessorStep$4.run(ProcessorStep.java:120)
at org.neo4j.unsafe.impl.batchimport.staging.ProcessorStep$4.run(ProcessorStep.java:102)
at org.neo4j.unsafe.impl.batchimport.executor.DynamicTaskExecutor$Processor.run(DynamicTaskExecutor.java:237)
It disappear when I remove some files to the import, but it's not link a file in particular, then not an format issue.
Any idea?
Thanks