Solved. It was a 'misconfigured' solrconfig.xml Had this: <requestHandler name="/update" class="solr.JsonUpdateRequestHandler"/>
Fixed backing to default and adding a path for json updates: <requestHandler name="/update" class="solr.UpdateRequestHandler" /> <requestHandler name="/update/json" class="solr.JsonUpdateRequestHandler"> <lst name="defaults"> <str name="stream.contentType">application/json</str> </lst> </requestHandler> -- View this message in context: http://lucene.472066.n3.nabble.com/Error-while-trying-to-index-doc-on-replica-tp4111504p4111534.html Sent from the Solr - User mailing list archive at Nabble.com.