Yes, Id is an unique field in my schema. I found following Jira issue: https://issues.apache.org/jira/browse/LUCENE-6336
It looks related to me. It does not mention that it was fixed. Is it fixed in Solr 6.1? I'm using Solr 6.1 -- Sent from: http://lucene.472066.n3.nabble.com/Solr-User-f472068.html