diff --git a/src/main/java/org/gcube/portlets/user/td/gwtservice/server/TDGWTServiceImpl.java b/src/main/java/org/gcube/portlets/user/td/gwtservice/server/TDGWTServiceImpl.java
index 2bc1b0e..fb31f3f 100644
--- a/src/main/java/org/gcube/portlets/user/td/gwtservice/server/TDGWTServiceImpl.java
+++ b/src/main/java/org/gcube/portlets/user/td/gwtservice/server/TDGWTServiceImpl.java
@@ -1135,7 +1135,12 @@ public class TDGWTServiceImpl extends RemoteServiceServlet implements
 			Table table = service.getLastTable(new TabularResourceId(Long
 					.valueOf(trId.getId())));
 			logger.debug("Table retrieved: " + table);
-
+			if(table==null){
+				logger.error("Last Table is Null: "+ Long
+						.valueOf(trId.getId()));
+				new TDGWTServiceException("Last Table is Null");
+			}
+			
 			Table viewTable = null;
 
 			if (table.contains(DatasetViewTableMetadata.class)) {
diff --git a/src/main/java/org/gcube/portlets/user/td/gwtservice/shared/monitor/OperationMonitorCreator.java b/src/main/java/org/gcube/portlets/user/td/gwtservice/shared/monitor/OperationMonitorCreator.java
index efba032..251e049 100644
--- a/src/main/java/org/gcube/portlets/user/td/gwtservice/shared/monitor/OperationMonitorCreator.java
+++ b/src/main/java/org/gcube/portlets/user/td/gwtservice/shared/monitor/OperationMonitorCreator.java
@@ -113,7 +113,14 @@ public class OperationMonitorCreator {
 					SessionUtil.removeStartedTask(session, taskWrapper);
 					postOperation(operationMonitor);
 				} else {
-					TaskStatus status = taskWrapper.getTask().getStatus();
+				
+					TaskStatus status=null;
+					try {
+						status=taskWrapper.getTask().getStatus();
+					} catch(Throwable e){
+						logger.debug("Error retrieving task status: "+taskWrapper.getTask()+"  "+e.getLocalizedMessage());
+						e.printStackTrace();
+					}
 					if (status == null) {
 						logger.debug("Services TaskStatus : null");
 						throw new TDGWTServiceException(
@@ -278,8 +285,18 @@ public class OperationMonitorCreator {
 					new Long(trId.getId()));
 
 			TabularResource tr = service.getTabularResource(tabularResourceId);
+			if(tr==null){
+				logger.error("Tabular Resource Null [id="+trId.getId()+"]");
+				throw new TDGWTServiceException("Tabular Resource Null "+trId);
+			}
+			
 			Table table = service.getLastTable(tabularResourceId);
-
+			if(table==null){
+				logger.error("Last Table Null");
+				throw new TDGWTServiceException("Last Table Null for "+tr);
+			}
+			
+			
 			Table viewTable = null;
 
 			if (table.contains(DatasetViewTableMetadata.class)) {
@@ -319,7 +336,7 @@ public class OperationMonitorCreator {
 					"Security exception, you haven't rights!");
 		} catch (Throwable e) {
 			e.printStackTrace();
-			throw new TDGWTServiceException("Error in Client Library Request: "
+			throw new TDGWTServiceException("Error Retrieving Basic Data: "
 					+ e.getLocalizedMessage());
 		}
 	}