diff --git a/src/main/java/org/gcube/informationsystem/resourceregistry/er/ERManagement.java b/src/main/java/org/gcube/informationsystem/resourceregistry/er/ERManagement.java
index adfb5a8..e6d0174 100644
--- a/src/main/java/org/gcube/informationsystem/resourceregistry/er/ERManagement.java
+++ b/src/main/java/org/gcube/informationsystem/resourceregistry/er/ERManagement.java
@@ -387,6 +387,29 @@ public abstract class ERManagement<ERType extends ER, El extends Element> {
 			}
 		}
 	}
+	
+	
+	public boolean exists() throws ERNotFoundException, ResourceRegistryException {
+		try {
+			orientGraph = ContextUtility.getActualSecurityContextGraph(PermissionMode.READER);
+
+			getElement();
+
+			if(element==null){
+				return false;
+			}else{
+				return true;
+			}
+		} catch (ResourceRegistryException e) {
+			throw e;
+		} catch (Exception e) {
+			throw new ResourceRegistryException(e);
+		} finally {
+			if (orientGraph != null) {
+				orientGraph.shutdown();
+			}
+		}
+	}
 
 	public String read() throws ERNotFoundException,
 			ResourceRegistryException {
diff --git a/src/main/java/org/gcube/informationsystem/resourceregistry/er/entity/EntityManagement.java b/src/main/java/org/gcube/informationsystem/resourceregistry/er/entity/EntityManagement.java
index bc21398..b2151ed 100644
--- a/src/main/java/org/gcube/informationsystem/resourceregistry/er/entity/EntityManagement.java
+++ b/src/main/java/org/gcube/informationsystem/resourceregistry/er/entity/EntityManagement.java
@@ -73,6 +73,12 @@ public abstract class EntityManagement<E extends Entity> extends
 
 		try {
 
+			if(oClass.isAbstract()){
+				String error = String.format("Trying to create an instance of %s of type %s which is abstract. The operation will be aborted.", 
+						baseType, erType);
+				throw new ResourceRegistryException(error);
+			}
+			
 			Vertex vertexEntity = orientGraph.addVertex("class:" + erType);
 
 			try {
@@ -164,7 +170,16 @@ public abstract class EntityManagement<E extends Entity> extends
 	@SuppressWarnings({ "rawtypes", "unchecked" })
 	public static EntityManagement getEntityManagement(OrientGraph orientGraph,
 			Vertex vertex) throws ResourceRegistryException {
-		OrientVertexType orientVertexType = ((OrientVertex) vertex).getType();
+		
+		OrientVertexType orientVertexType = null;
+		try {
+			orientVertexType = ((OrientVertex) vertex).getType();
+		}catch (Exception e) {
+			String error = String.format("Unable to detect type of %s. This is really strage please contact the administrator", vertex.toString()); 
+			logger.error(error, e);
+			throw new ResourceRegistryException(error);
+		}
+		
 		EntityManagement entityManagement = null;
 		if (orientVertexType.isSubClassOf(Resource.NAME)) {
 			entityManagement = new ResourceManagement(orientGraph);
@@ -221,8 +236,12 @@ public abstract class EntityManagement<E extends Entity> extends
 		for(Vertex vertex : iterable){
 			@SuppressWarnings("rawtypes")
 			EntityManagement entityManagement = getEntityManagement(orientGraph, vertex);
-			JSONObject jsonObject =  entityManagement.serializeAsJson();
-			jsonArray.put(jsonObject);
+			try {
+				JSONObject jsonObject =  entityManagement.serializeAsJson();
+				jsonArray.put(jsonObject);
+			}catch (ResourceRegistryException e) {
+				logger.error("Unable to correctly serialize {}. It will be excluded from results. This is really strange and should not occur.", vertex.toString());
+			}
 		}
 		return jsonArray.toString();
 	}
diff --git a/src/main/java/org/gcube/informationsystem/resourceregistry/er/entity/ResourceManagement.java b/src/main/java/org/gcube/informationsystem/resourceregistry/er/entity/ResourceManagement.java
index 6e64341..98e5036 100644
--- a/src/main/java/org/gcube/informationsystem/resourceregistry/er/entity/ResourceManagement.java
+++ b/src/main/java/org/gcube/informationsystem/resourceregistry/er/entity/ResourceManagement.java
@@ -68,9 +68,13 @@ public class ResourceManagement extends EntityManagement<Resource> {
 			RelationManagement relationManagement = RelationManagement
 					.getRelationManagement(orientGraph, edge);
 			if (relationManagement instanceof ConsistsOfManagement) {
-				JSONObject consistsOf = relationManagement
-						.serializeAsJson();
-				sourceResource = addConsistsOf(sourceResource, consistsOf);
+				try {
+					JSONObject consistsOf = relationManagement
+							.serializeAsJson();
+					sourceResource = addConsistsOf(sourceResource, consistsOf);
+				}catch (ResourceRegistryException e) {
+					logger.error("Unable to correctly serialize {}. It will be excluded from results. This is really strange and should not occur.", edge.toString());
+				}
 				
 			}
 			/*
diff --git a/src/main/java/org/gcube/informationsystem/resourceregistry/er/relation/RelationManagement.java b/src/main/java/org/gcube/informationsystem/resourceregistry/er/relation/RelationManagement.java
index ffe5425..b8ea7a3 100644
--- a/src/main/java/org/gcube/informationsystem/resourceregistry/er/relation/RelationManagement.java
+++ b/src/main/java/org/gcube/informationsystem/resourceregistry/er/relation/RelationManagement.java
@@ -12,7 +12,6 @@ import java.util.Map;
 import java.util.UUID;
 
 import org.codehaus.jettison.json.JSONArray;
-import org.codehaus.jettison.json.JSONException;
 import org.codehaus.jettison.json.JSONObject;
 import org.gcube.informationsystem.model.embedded.PropagationConstraint;
 import org.gcube.informationsystem.model.embedded.PropagationConstraint.AddConstraint;
@@ -98,14 +97,13 @@ public abstract class RelationManagement<R extends Relation> extends
 		JSONObject relation = serializeSelfOnly();
 
 		Vertex target = element.getVertex(Direction.IN);
-		EntityManagement entityManagement = EntityManagement
-				.getEntityManagement(orientGraph, target);
-
 		try {
+			EntityManagement entityManagement = EntityManagement
+					.getEntityManagement(orientGraph, target);
 			relation.put(Relation.TARGET_PROPERTY,
 					entityManagement.serializeAsJson());
-		} catch (JSONException e) {
-			throw new ResourceRegistryException(e);
+		} catch (Exception e) {
+			logger.error("Unable to correctly serialize {}. It will be excluded from results. This is really strange and should not occur.", target.toString());
 		}
 
 		return relation;