diff --git a/core/include/Catalogue/CatalogueController.h b/core/include/Catalogue/CatalogueController.h
index 3ac6945..b9b2835 100644
--- a/core/include/Catalogue/CatalogueController.h
+++ b/core/include/Catalogue/CatalogueController.h
@@ -50,6 +50,7 @@ public:
     //    void trashEvent(std::shared_ptr<DBEvent> event);
     //    void restore(QUuid eventId);
     void saveEvent(std::shared_ptr<DBEvent> event);
+    bool eventHasChanges(std::shared_ptr<DBEvent> event) const;
 
     // Catalogue
     //    bool createCatalogue(const QString &name, QVector<QUuid> eventList);
diff --git a/core/src/Catalogue/CatalogueController.cpp b/core/src/Catalogue/CatalogueController.cpp
index cc47646..b2892b7 100644
--- a/core/src/Catalogue/CatalogueController.cpp
+++ b/core/src/Catalogue/CatalogueController.cpp
@@ -37,6 +37,10 @@ public:
     QStringList m_RepositoryList;
     CatalogueController *m_Q;
 
+    QSet<QString> m_EventKeysWithChanges;
+
+    QString eventUniqueKey(const std::shared_ptr<DBEvent> &event) const;
+
     void copyDBtoDB(const QString &dbFrom, const QString &dbTo);
     QString toWorkRepository(QString repository);
     QString toSyncRepository(QString repository);
@@ -137,6 +141,9 @@ void CatalogueController::updateEvent(std::shared_ptr<DBEvent> event)
 {
     event->setRepository(impl->toWorkRepository(event->getRepository()));
 
+    auto uniqueId = impl->eventUniqueKey(event);
+    impl->m_EventKeysWithChanges.insert(uniqueId);
+
     impl->m_CatalogueDao.updateEvent(*event);
 }
 
@@ -180,6 +187,12 @@ void CatalogueController::addEvent(std::shared_ptr<DBEvent> event)
 void CatalogueController::saveEvent(std::shared_ptr<DBEvent> event)
 {
     impl->saveEvent(event, true);
+    impl->m_EventKeysWithChanges.remove(impl->eventUniqueKey(event));
+}
+
+bool CatalogueController::eventHasChanges(std::shared_ptr<DBEvent> event) const
+{
+    return impl->m_EventKeysWithChanges.contains(impl->eventUniqueKey(event));
 }
 
 std::list<std::shared_ptr<DBCatalogue> >
@@ -233,6 +246,7 @@ void CatalogueController::saveAll()
     }
 
     impl->savAllDB();
+    impl->m_EventKeysWithChanges.clear();
 }
 
 QByteArray
@@ -306,6 +320,12 @@ void CatalogueController::initialize()
     qCDebug(LOG_CatalogueController()) << tr("CatalogueController init END");
 }
 
+QString CatalogueController::CatalogueControllerPrivate::eventUniqueKey(
+    const std::shared_ptr<DBEvent> &event) const
+{
+    return event->getUniqId().toString().append(event->getRepository());
+}
+
 void CatalogueController::CatalogueControllerPrivate::copyDBtoDB(const QString &dbFrom,
                                                                  const QString &dbTo)
 {
diff --git a/gui/src/Catalogue/CatalogueEventsModel.cpp b/gui/src/Catalogue/CatalogueEventsModel.cpp
index 9c8f46a..655f356 100644
--- a/gui/src/Catalogue/CatalogueEventsModel.cpp
+++ b/gui/src/Catalogue/CatalogueEventsModel.cpp
@@ -24,7 +24,6 @@ const auto EVENT_PRODUCT_ITEM_TYPE = 2;
 struct CatalogueEventsModel::CatalogueEventsModelPrivate {
     QVector<std::shared_ptr<DBEvent> > m_Events;
     std::unordered_map<DBEvent *, QVector<std::shared_ptr<DBEventProduct> > > m_EventProducts;
-    std::unordered_set<std::shared_ptr<DBEvent> > m_EventsWithChanges;
 
     QStringList columnNames()
     {
@@ -35,8 +34,8 @@ struct CatalogueEventsModel::CatalogueEventsModelPrivate {
     QVariant sortData(int col, const std::shared_ptr<DBEvent> &event) const
     {
         if (col == (int)CatalogueEventsModel::Column::Validation) {
-            return m_EventsWithChanges.find(event) != m_EventsWithChanges.cend() ? true
-                                                                                 : QVariant();
+            auto hasChanges = sqpApp->catalogueController().eventHasChanges(event);
+            return hasChanges ? true : QVariant();
         }
 
         return eventData(col, event);
@@ -136,7 +135,6 @@ void CatalogueEventsModel::setEvents(const QVector<std::shared_ptr<DBEvent> > &e
 
     impl->m_Events = events;
     impl->m_EventProducts.clear();
-    impl->m_EventsWithChanges.clear();
     for (auto event : events) {
         impl->parseEventProduct(event);
     }
@@ -195,7 +193,6 @@ void CatalogueEventsModel::removeEvent(const std::shared_ptr<DBEvent> &event)
         beginRemoveRows(QModelIndex(), index, index);
         impl->m_Events.removeAt(index);
         impl->m_EventProducts.erase(event.get());
-        impl->m_EventsWithChanges.erase(event);
         endRemoveRows();
     }
 }
@@ -232,22 +229,6 @@ QModelIndex CatalogueEventsModel::indexOf(const std::shared_ptr<DBEvent> &event)
     return QModelIndex();
 }
 
-void CatalogueEventsModel::setEventHasChanges(const std::shared_ptr<DBEvent> &event,
-                                              bool hasChanges)
-{
-    if (hasChanges) {
-        impl->m_EventsWithChanges.insert(event);
-    }
-    else {
-        impl->m_EventsWithChanges.erase(event);
-    }
-}
-
-bool CatalogueEventsModel::eventsHasChanges(const std::shared_ptr<DBEvent> &event) const
-{
-    return impl->m_EventsWithChanges.find(event) != impl->m_EventsWithChanges.cend();
-}
-
 QModelIndex CatalogueEventsModel::index(int row, int column, const QModelIndex &parent) const
 {
     if (!hasIndex(row, column, parent)) {
diff --git a/gui/src/Catalogue/CatalogueEventsWidget.cpp b/gui/src/Catalogue/CatalogueEventsWidget.cpp
index 0a5f9b9..1ebf1ed 100644
--- a/gui/src/Catalogue/CatalogueEventsWidget.cpp
+++ b/gui/src/Catalogue/CatalogueEventsWidget.cpp
@@ -29,11 +29,18 @@ struct CatalogueEventsWidget::CatalogueEventsWidgetPrivate {
 
     VisualizationWidget *m_VisualizationWidget = nullptr;
 
-    void setEvents(const QVector<std::shared_ptr<DBEvent> > &events, QTreeView *treeView)
+    void setEvents(const QVector<std::shared_ptr<DBEvent> > &events, CatalogueEventsWidget *widget)
     {
-        treeView->setSortingEnabled(false);
+        widget->ui->treeView->setSortingEnabled(false);
         m_Model->setEvents(events);
-        treeView->setSortingEnabled(true);
+        widget->ui->treeView->setSortingEnabled(true);
+
+        for (auto event : events) {
+            if (sqpApp->catalogueController().eventHasChanges(event)) {
+                auto index = m_Model->indexOf(event);
+                widget->setEventChanges(event, true);
+            }
+        }
     }
 
     void addEvent(const std::shared_ptr<DBEvent> &event, QTreeView *treeView)
@@ -290,7 +297,7 @@ CatalogueEventsWidget::CatalogueEventsWidget(QWidget *parent)
     connect(impl->m_Model, &CatalogueEventsModel::modelSorted, [this]() {
         auto allEvents = impl->m_Model->events();
         for (auto event : allEvents) {
-            setEventChanges(event, impl->m_Model->eventsHasChanges(event));
+            setEventChanges(event, sqpApp->catalogueController().eventHasChanges(event));
         }
     });
 
@@ -332,8 +339,10 @@ void CatalogueEventsWidget::setEventChanges(const std::shared_ptr<DBEvent> &even
                     [this, event]() { setEventChanges(event, false); });
                 ui->treeView->setIndexWidget(validationIndex, widget);
             }
-
-            impl->m_Model->setEventHasChanges(event, hasChanges);
+        }
+        else {
+            // Note: the widget is destroyed
+            ui->treeView->setIndexWidget(validationIndex, nullptr);
         }
     }
     else {
@@ -375,7 +384,7 @@ void CatalogueEventsWidget::populateWithCatalogues(
         }
     }
 
-    impl->setEvents(events, ui->treeView);
+    impl->setEvents(events, this);
 }
 
 void CatalogueEventsWidget::populateWithAllEvents()
@@ -389,13 +398,13 @@ void CatalogueEventsWidget::populateWithAllEvents()
         events << event;
     }
 
-    impl->setEvents(events, ui->treeView);
+    impl->setEvents(events, this);
 }
 
 void CatalogueEventsWidget::clear()
 {
     impl->m_DisplayedCatalogues.clear();
-    impl->setEvents({}, ui->treeView);
+    impl->setEvents({}, this);
 }
 
 void CatalogueEventsWidget::refresh()