diff --git a/pom.xml b/pom.xml
index 1bb8e45..b27307a 100644
--- a/pom.xml
+++ b/pom.xml
@@ -94,6 +94,13 @@
 			<scope>provided</scope>
 		</dependency>
 
+		<!-- JSON PARSER -->
+		<dependency>
+			<groupId>org.json</groupId>
+			<artifactId>json</artifactId>
+			<version>20090211</version>
+		</dependency>
+
 		<!-- LOGGER -->
 		<dependency>
 			<groupId>org.slf4j</groupId>
diff --git a/src/main/java/org/gcube/common/workspacetaskexecutor/shared/TaskParameter.java b/src/main/java/org/gcube/common/workspacetaskexecutor/shared/TaskParameter.java
index a2ee54a..acd331e 100644
--- a/src/main/java/org/gcube/common/workspacetaskexecutor/shared/TaskParameter.java
+++ b/src/main/java/org/gcube/common/workspacetaskexecutor/shared/TaskParameter.java
@@ -23,8 +23,8 @@ public class TaskParameter implements Serializable{
 	private static final long serialVersionUID = 3607328256110736864L;
 	private String key;
 	private String value;
-	@JsonIgnoreProperties
-	private List<String> defaultValues; //optional
+	@JsonIgnoreProperties //optional
+	private List<String> defaultValues;
 	private TaskParameterType type;
 
 	/**
diff --git a/src/test/java/org/gcube/common/workspacetaskexecutor/TestDataMinerTaskExecutor.java b/src/test/java/org/gcube/common/workspacetaskexecutor/TestDataMinerTaskExecutor.java
index fc7d96a..0ee49b5 100644
--- a/src/test/java/org/gcube/common/workspacetaskexecutor/TestDataMinerTaskExecutor.java
+++ b/src/test/java/org/gcube/common/workspacetaskexecutor/TestDataMinerTaskExecutor.java
@@ -5,15 +5,12 @@ package org.gcube.common.workspacetaskexecutor;
 
 import java.io.IOException;
 import java.util.ArrayList;
+import java.util.Arrays;
 import java.util.List;
 import java.util.Random;
 import java.util.UUID;
 
-import org.gcube.common.homelibrary.home.exceptions.HomeNotFoundException;
-import org.gcube.common.homelibrary.home.exceptions.InternalErrorException;
 import org.gcube.common.homelibrary.home.workspace.WorkspaceItem;
-import org.gcube.common.homelibrary.home.workspace.exceptions.ItemNotFoundException;
-import org.gcube.common.homelibrary.home.workspace.exceptions.WorkspaceFolderNotFoundException;
 import org.gcube.common.workspacetaskexecutor.dataminer.WorkspaceDataMinerTaskExecutor;
 import org.gcube.common.workspacetaskexecutor.shared.TaskParameter;
 import org.gcube.common.workspacetaskexecutor.shared.TaskParameterType;
@@ -40,7 +37,7 @@ public class TestDataMinerTaskExecutor {
 	public static String USERNAME = "francesco.mangiacrapa";
 	public static String SCOPE = "/gcube/devsec";
 
-	public static String WORKSPACE_FOLDER_ID = "f5c2f5ab-5c35-4418-8e60-d48d173538ed";
+	public static String WORKSPACE_FOLDER_ID = "682ff48e-0cc9-44df-884d-185fabe8909b";
 
 	private static JsonUtil jUtil = new JsonUtil();
 
@@ -93,7 +90,9 @@ public class TestDataMinerTaskExecutor {
 
 	public static void main(String[] args) {
 
-//		ScopeProvider.instance.set(SCOPE);
+		jsonCheck();
+
+		//ScopeProvider.instance.set(SCOPE);
 //		listDummyConf = gelDummyListOfConfigurations(3);
 //		WorkspaceDataMinerTaskExecutor exec =  WorkspaceDataMinerTaskExecutor.getInstance();
 //		exec.withOwner(USERNAME);
@@ -148,7 +147,7 @@ public class TestDataMinerTaskExecutor {
 //			e.printStackTrace();
 //		}
 
-		//checkGubeProperties(gelDummyListOfConfigurations());
+		//checkGubeProperties(null);
 
 
 //		try {
@@ -195,13 +194,15 @@ public class TestDataMinerTaskExecutor {
 		try {
 			WorkspaceItem workspaceItem = WsUtil.getItem(USERNAME, WORKSPACE_FOLDER_ID);
 
-			JSONArray jsonArray = jUtil.toJSONArray(listConfigurations);
-			System.out.println("Json array to save: "+jsonArray);
-			WsUtil.setPropertyValue(workspaceItem, WorkspaceDataMinerTaskExecutor.WS_DM_TASK_TASK_CONF, jsonArray.toString());
+			/*if(listConfigurations!=null){
+				JSONArray jsonArray = jUtil.toJSONArray(listConfigurations);
+				System.out.println("Json array to save: "+jsonArray);
+				WsUtil.setPropertyValue(workspaceItem, WorkspaceDataMinerTaskExecutor.WS_DM_TASK_TASK_CONF, jsonArray.toString());
+			}
 
 			//GET
 			String jsonArrayConf = WsUtil.getPropertyValue(workspaceItem, WorkspaceDataMinerTaskExecutor.WS_DM_TASK_TASK_CONF);
-			System.out.println("Json array read from "+WorkspaceDataMinerTaskExecutor.WS_DM_TASK_TASK_CONF+": "+jsonArray);
+			System.out.println("Json array read from "+WorkspaceDataMinerTaskExecutor.WS_DM_TASK_TASK_CONF+": "+jsonArrayConf);
 
 
 			TypeReference<List<TaskConfiguration>> mapType = new TypeReference<List<TaskConfiguration>>() {};
@@ -209,15 +210,9 @@ public class TestDataMinerTaskExecutor {
 			System.out.println("Json array to listUnM...");
 			for (TaskConfiguration taskConfiguration : listUnM) {
 				System.out.println(taskConfiguration);
-			}
+			}*/
 		}
-		catch (WorkspaceFolderNotFoundException | ItemNotFoundException
-						| InternalErrorException | HomeNotFoundException | JsonProcessingException | JSONException e) {
-			// TODO Auto-generated catch block
-			e.printStackTrace();
-		}
-		catch (IOException e) {
-			// TODO Auto-generated catch block
+		catch (Exception e){
 			e.printStackTrace();
 		}
 	}
@@ -242,19 +237,22 @@ public class TestDataMinerTaskExecutor {
 		tp.setValue("this is the public link "+index);
 		tp.setType(new TaskParameterType(ParameterType.FILE.toString()));
 
+
 		listParameters.add(tp);
 
 		TaskParameter tp2 = new TaskParameter();
 		tp2.setKey("key"+index);
 		tp2.setValue("value "+index);
 		tp2.setType(types.get(new Random().nextInt(types.size())));
+		tp2.setDefaultValues(Arrays.asList("value 1", "value2"));
 		listParameters.add(tp2);
 
+
 		return new TaskConfiguration(index+"", UUID.randomUUID().toString(), index+"name", null, USERNAME, SCOPE, "my token", WORKSPACE_FOLDER_ID, listParameters);
 	}
 
 
-	public static List<TaskConfiguration> gelDummyListOfConfigurations(int total){
+	public static List<TaskConfiguration> getDummyListOfConfigurations(int total){
 		List<TaskConfiguration> listConfigurations = new ArrayList<>(total);
 		for (int i=0; i<total; i++) {
 			TaskConfiguration c  = createDummyConfiguration(i);
@@ -266,10 +264,10 @@ public class TestDataMinerTaskExecutor {
 	public static void jsonCheck(){
 
 
-		List<TaskConfiguration> listConfigurations = gelDummyListOfConfigurations(3);
+		List<TaskConfiguration> listConfigurations = getDummyListOfConfigurations(3);
 		try {
 			JSONArray jsonArray = jUtil.toJSONArray(listConfigurations);
-			System.out.println("Json array: "+jsonArray);
+			System.out.println("Json array: "+jsonArray.toString(4));
 			TypeReference<List<TaskConfiguration>> mapType = new TypeReference<List<TaskConfiguration>>() {};
 			List<TaskConfiguration> listUnM = jUtil.readList(jsonArray.toString(), mapType);
 			System.out.println("Json array to listUnM...");