diff --git a/apps/scholexplorer-api/src/main/java/eu/dnetlib/scholix/api/index/ScholixIndexManager.java b/apps/scholexplorer-api/src/main/java/eu/dnetlib/scholix/api/index/ScholixIndexManager.java
index 12aefd10..a241025e 100644
--- a/apps/scholexplorer-api/src/main/java/eu/dnetlib/scholix/api/index/ScholixIndexManager.java
+++ b/apps/scholexplorer-api/src/main/java/eu/dnetlib/scholix/api/index/ScholixIndexManager.java
@@ -163,7 +163,6 @@ public class ScholixIndexManager {
             final SearchHits<ScholixFlat> hits = client.search(searchQuery, ScholixFlat.class, IndexCoordinates.of(elasticSearchProperties.getIndexName()));
 
             final Aggregations aggregations = hits.getAggregations();
-            connectionPool.returnResource(resource);
             if (aggregations == null)
                 return null;
 
diff --git a/pom.xml b/pom.xml
index 4132111a..c6c5190a 100644
--- a/pom.xml
+++ b/pom.xml
@@ -453,7 +453,7 @@
 		<project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
 		<maven.compiler.plugin.version>3.6.0</maven.compiler.plugin.version>
 		<java.version>1.8</java.version>
-		<dhp-schemas-version>3.16.1-SNAPSHOT</dhp-schemas-version>
+		<dhp-schemas-version>3.17.2-FLAT-SNAPSHOT</dhp-schemas-version>
 		<apache.solr.version>7.1.0</apache.solr.version>
 		<mongodb.driver.version>3.4.2</mongodb.driver.version>
 		<prometheus.version>0.10.0</prometheus.version>