Solr collection indexed to pdf in hdfs throws error during solr restart

When I restart Solr it throws the following error. Solr collection indexed to pdf in hdfs throws error during solr restart. Error java.util.concurrent.ExecutionException: org.apache.solr.common.SolrException: Unable to create core [PDFIndex] at java.util.concurrent.FutureTask.report(Futur

Solr collection indexed to pdf in hdfs throws error during solr restart

When I restart Solr it throws the following error. Solr collection indexed to pdf in hdfs throws error during solr restart. Error java.util.concurrent.ExecutionException: org.apache.solr.common.SolrException: Unable to create core [PDFIndex] at java.util.concurrent.FutureTask.report(Futur