diff --git a/migration/i7.1z/oracle/202007211126_IDEMPIERE-4339_PR.sql b/migration/i7.1z/oracle/202007211126_IDEMPIERE-4339_PR.sql
new file mode 100644
index 0000000000..a1bd6ba979
--- /dev/null
+++ b/migration/i7.1z/oracle/202007211126_IDEMPIERE-4339_PR.sql
@@ -0,0 +1,26 @@
+SET SQLBLANKLINES ON
+SET DEFINE OFF
+
+-- Jul 21, 2020, 11:03:05 AM CEST
+UPDATE AD_Process SET Name='Create Default Parameters',Updated=TO_DATE('2020-07-21 11:03:05','YYYY-MM-DD HH24:MI:SS'),UpdatedBy=100 WHERE AD_Process_ID=200119
+;
+
+-- Jul 21, 2020, 11:03:20 AM CEST
+UPDATE AD_Element SET Name='Create Default Parameters', PrintName='Create Default Parameters',Updated=TO_DATE('2020-07-21 11:03:20','YYYY-MM-DD HH24:MI:SS'),UpdatedBy=100 WHERE AD_Element_ID=203423
+;
+
+-- Jul 21, 2020, 11:03:20 AM CEST
+UPDATE AD_Column SET ColumnName='InsertParameters', Name='Create Default Parameters', Description=NULL, Help=NULL, Placeholder=NULL WHERE AD_Element_ID=203423
+;
+
+-- Jul 21, 2020, 11:03:20 AM CEST
+UPDATE AD_Field SET Name='Create Default Parameters', Description=NULL, Help=NULL, Placeholder=NULL WHERE AD_Column_ID IN (SELECT AD_Column_ID FROM AD_Column WHERE AD_Element_ID=203423) AND IsCentrallyMaintained='Y'
+;
+
+-- Jul 21, 2020, 11:22:14 AM CEST
+UPDATE AD_Field SET DisplayLogic='@WS_WebService_ID.Value@=''ModelADService''', AD_Reference_Value_ID=NULL, AD_Val_Rule_ID=NULL, IsToolbarButton=NULL,Updated=TO_DATE('2020-07-21 11:22:14','YYYY-MM-DD HH24:MI:SS'),UpdatedBy=100 WHERE AD_Field_ID=206417
+;
+
+SELECT register_migration_script('202007211126_IDEMPIERE-4339_PR.sql') FROM dual
+;
+
diff --git a/migration/i7.1z/postgresql/202007211126_IDEMPIERE-4339_PR.sql b/migration/i7.1z/postgresql/202007211126_IDEMPIERE-4339_PR.sql
new file mode 100644
index 0000000000..ebcbc94a74
--- /dev/null
+++ b/migration/i7.1z/postgresql/202007211126_IDEMPIERE-4339_PR.sql
@@ -0,0 +1,23 @@
+-- Jul 21, 2020, 11:03:05 AM CEST
+UPDATE AD_Process SET Name='Create Default Parameters',Updated=TO_TIMESTAMP('2020-07-21 11:03:05','YYYY-MM-DD HH24:MI:SS'),UpdatedBy=100 WHERE AD_Process_ID=200119
+;
+
+-- Jul 21, 2020, 11:03:20 AM CEST
+UPDATE AD_Element SET Name='Create Default Parameters', PrintName='Create Default Parameters',Updated=TO_TIMESTAMP('2020-07-21 11:03:20','YYYY-MM-DD HH24:MI:SS'),UpdatedBy=100 WHERE AD_Element_ID=203423
+;
+
+-- Jul 21, 2020, 11:03:20 AM CEST
+UPDATE AD_Column SET ColumnName='InsertParameters', Name='Create Default Parameters', Description=NULL, Help=NULL, Placeholder=NULL WHERE AD_Element_ID=203423
+;
+
+-- Jul 21, 2020, 11:03:20 AM CEST
+UPDATE AD_Field SET Name='Create Default Parameters', Description=NULL, Help=NULL, Placeholder=NULL WHERE AD_Column_ID IN (SELECT AD_Column_ID FROM AD_Column WHERE AD_Element_ID=203423) AND IsCentrallyMaintained='Y'
+;
+
+-- Jul 21, 2020, 11:22:14 AM CEST
+UPDATE AD_Field SET DisplayLogic='@WS_WebService_ID.Value@=''ModelADService''', AD_Reference_Value_ID=NULL, AD_Val_Rule_ID=NULL, IsToolbarButton=NULL,Updated=TO_TIMESTAMP('2020-07-21 11:22:14','YYYY-MM-DD HH24:MI:SS'),UpdatedBy=100 WHERE AD_Field_ID=206417
+;
+
+SELECT register_migration_script('202007211126_IDEMPIERE-4339_PR.sql') FROM dual
+;
+
diff --git a/org.idempiere.webservices/WEB-INF/src/org/compiere/model/MWebServiceType.java b/org.idempiere.webservices/WEB-INF/src/org/compiere/model/MWebServiceType.java
index 1caba4b293..b105afcf9b 100644
--- a/org.idempiere.webservices/WEB-INF/src/org/compiere/model/MWebServiceType.java
+++ b/org.idempiere.webservices/WEB-INF/src/org/compiere/model/MWebServiceType.java
@@ -50,7 +50,7 @@ public class MWebServiceType extends X_WS_WebServiceType
 	/**
 	 * 
 	 */
-	private static final long serialVersionUID = 7216001796414414950L;
+	private static final long serialVersionUID = -2713868996404459577L;
 
 	/**	Parameters	*/
 	private MWebServicePara[]	m_para = null;
@@ -287,20 +287,20 @@ public class MWebServiceType extends X_WS_WebServiceType
 		return m_inputFieldMap.get(colName);
 	}
 
-	public static void insertParameters (Properties ctx, MWebServiceType ws, String trxName) {
+	public void insertParameters() {
 
-		if ("ModelADService".equals(ws.getWS_WebService().getValue())) {
-			String method = ws.getWS_WebServiceMethod().getValue();
+		MWebService ws = MWebService.get(getCtx(), getWS_WebService_ID());
+		if (ws != null && "ModelADService".equals(ws.getValue())) {
+			X_WS_WebServiceMethod wsm = new X_WS_WebServiceMethod(getCtx(), getWS_WebServiceMethod_ID(), get_TrxName());
+			String method = wsm.getValue();
 
 			if ("getList".equals(method)) {
-				ws.addWsParameter("AD_Reference_ID", X_WS_WebService_Para.PARAMETERTYPE_Free, "");
-			}
-			else if ("runProcess".equals(method)) {
-				ws.addWsParameter("AD_Process_ID", X_WS_WebService_Para.PARAMETERTYPE_Constant, ""); // can't fill it as the process is unknown
-				ws.addWsParameter("AD_Menu_ID", X_WS_WebService_Para.PARAMETERTYPE_Constant, "0");
-				ws.addWsParameter("AD_Record_ID", X_WS_WebService_Para.PARAMETERTYPE_Free, "");
-			}
-			else {
+				addWsParameter("AD_Reference_ID", X_WS_WebService_Para.PARAMETERTYPE_Free, "");
+			} else if ("runProcess".equals(method)) {
+				addWsParameter("AD_Process_ID", X_WS_WebService_Para.PARAMETERTYPE_Constant, ""); // can't fill it as the process is unknown
+				addWsParameter("AD_Menu_ID", X_WS_WebService_Para.PARAMETERTYPE_Constant, "0");
+				addWsParameter("AD_Record_ID", X_WS_WebService_Para.PARAMETERTYPE_Free, "");
+			} else {
 				String value = "";
 				if ("createData".equals(method))
 					value = "Create";
@@ -313,9 +313,9 @@ public class MWebServiceType extends X_WS_WebServiceType
 				else if ("updateData".equals(method))
 					value = "Update";
 
-				ws.addWsParameter("TableName", X_WS_WebService_Para.PARAMETERTYPE_Constant, MTable.get(ctx, ws.getAD_Table_ID()).getTableName());
-				ws.addWsParameter("Action", X_WS_WebService_Para.PARAMETERTYPE_Constant, value);
-				ws.addWsParameter("RecordID", X_WS_WebService_Para.PARAMETERTYPE_Free, "");
+				addWsParameter("TableName", X_WS_WebService_Para.PARAMETERTYPE_Constant, MTable.get(getCtx(), getAD_Table_ID()).getTableName());
+				addWsParameter("Action", X_WS_WebService_Para.PARAMETERTYPE_Constant, value);
+				addWsParameter("RecordID", X_WS_WebService_Para.PARAMETERTYPE_Free, "");
 			}
 		}
 	}
diff --git a/org.idempiere.webservices/WEB-INF/src/org/idempiere/webservices/process/WebServiceTypeCreateParameters.java b/org.idempiere.webservices/WEB-INF/src/org/idempiere/webservices/process/WebServiceTypeCreateParameters.java
index 1db233e11e..33fc090537 100644
--- a/org.idempiere.webservices/WEB-INF/src/org/idempiere/webservices/process/WebServiceTypeCreateParameters.java
+++ b/org.idempiere.webservices/WEB-INF/src/org/idempiere/webservices/process/WebServiceTypeCreateParameters.java
@@ -33,19 +33,24 @@ import org.compiere.process.SvrProcess;
  */
 public class WebServiceTypeCreateParameters extends SvrProcess {
 
+	// The web service type (record on screen)
+	private int p_WS_WebServiceType_ID;
+
 	/**
 	 * Prepare - e.g., get Parameters.
 	 */
-	protected void prepare() {}
+	protected void prepare() {
+		p_WS_WebServiceType_ID = getRecord_ID();
+	}
 
 	/**
 	 *  Perform process.
 	 *  @return Message
 	 *  @throws Exception
 	 */
-	protected String doIt() throws Exception
-	{
-		MWebServiceType.insertParameters(getCtx(), new MWebServiceType(getCtx(), getRecord_ID(), get_TrxName()), get_TrxName());
+	protected String doIt() throws Exception {
+		MWebServiceType ws = new MWebServiceType(getCtx(), p_WS_WebServiceType_ID, get_TrxName());
+		ws.insertParameters();
 		return "@ProcessOK@";
 	} // doIt