diff --git a/projects/ucap-webmessenger-app/src/app/layouts/messenger/components/messages.component.ts b/projects/ucap-webmessenger-app/src/app/layouts/messenger/components/messages.component.ts
index 20fc8326..62a655ef 100644
--- a/projects/ucap-webmessenger-app/src/app/layouts/messenger/components/messages.component.ts
+++ b/projects/ucap-webmessenger-app/src/app/layouts/messenger/components/messages.component.ts
@@ -968,32 +968,36 @@ export class MessagesComponent implements OnInit, OnDestroy, AfterViewInit {
   onExistNewMessage(info: Info<EventJson>) {
     let message = '';
 
-    const senderUser = this.userInfoListSubject.value.filter(
-      user => user.seq === info.senderSeq
-    );
-    if (!!senderUser && senderUser.length > 0) {
-      message += `${senderUser[0].name} : `;
-    }
-    message += StringUtil.convertFinalEventMessage(
+    const contents = StringUtil.convertFinalEventMessage(
       info.type,
       info.sentMessageJson || info.sentMessage
     );
 
-    this.snackBarPreviewEvent = this.snackBarService.open(
-      message,
-      this.translateService.instant('common.messages.confirm'),
-      {
-        // duration: 3000,
-        verticalPosition: 'bottom',
-        horizontalPosition: 'center',
-        panelClass: ['chat-snackbar-class']
+    if (!!contents) {
+      const senderUser = this.userInfoListSubject.value.filter(
+        user => user.seq === info.senderSeq
+      );
+      if (!!senderUser && senderUser.length > 0) {
+        message += `${senderUser[0].name} : `;
       }
-    );
-    this.snackBarPreviewEvent.onAction().subscribe(() => {
-      this.chatMessages.initEventMore();
-      this.chatMessages.scrollToBottom();
-      this.snackBarPreviewEvent.dismiss();
-    });
+      message += contents;
+
+      this.snackBarPreviewEvent = this.snackBarService.open(
+        message,
+        this.translateService.instant('common.messages.confirm'),
+        {
+          // duration: 3000,
+          verticalPosition: 'bottom',
+          horizontalPosition: 'center',
+          panelClass: ['chat-snackbar-class']
+        }
+      );
+      this.snackBarPreviewEvent.onAction().subscribe(() => {
+        this.chatMessages.initEventMore();
+        this.chatMessages.scrollToBottom();
+        this.snackBarPreviewEvent.dismiss();
+      });
+    }
   }
 
   saveFile(
diff --git a/projects/ucap-webmessenger-app/src/app/services/notification.service.ts b/projects/ucap-webmessenger-app/src/app/services/notification.service.ts
index a13b3352..24d23d61 100644
--- a/projects/ucap-webmessenger-app/src/app/services/notification.service.ts
+++ b/projects/ucap-webmessenger-app/src/app/services/notification.service.ts
@@ -24,7 +24,8 @@ import {
   SSVC_TYPE_EVENT_CANCEL_NOTI,
   SSVC_TYPE_EVENT_DEL_RES,
   SSVC_TYPE_EVENT_SEND_RES,
-  SSVC_TYPE_EVENT_READ_RES
+  SSVC_TYPE_EVENT_READ_RES,
+  EventType
 } from '@ucap-webmessenger/protocol-event';
 import {
   InfoProtocolService,
@@ -248,30 +249,35 @@ export class AppNotificationService {
                         );
                         audio.play();
                       } else {
-                        const notiReq: NotificationRequest = {
-                          type: NotificationType.Event,
-                          seq: noti.roomSeq,
-                          title: this.translateService.instant(
-                            'notification.titleChatEventArrived'
-                          ),
-                          contents: StringUtil.convertFinalEventMessage(
-                            noti.eventType,
-                            noti.info.sentMessageJson
-                          ),
-                          image: '',
-                          useSound: [
-                            NotificationMethod.Sound,
-                            NotificationMethod.SoundAndAlert
-                          ].some(
-                            n => n === appUserInfo.settings.notification.method
-                          )
-                            ? true
-                            : false,
-                          displayTime:
-                            appUserInfo.settings.notification
-                              .alertExposureTime * 1000
-                        };
-                        this.nativeService.notify(notiReq);
+                        const contents = StringUtil.convertFinalEventMessage(
+                          noti.eventType,
+                          noti.info.sentMessageJson
+                        );
+
+                        if (!!contents) {
+                          const notiReq: NotificationRequest = {
+                            type: NotificationType.Event,
+                            seq: noti.roomSeq,
+                            title: this.translateService.instant(
+                              'notification.titleChatEventArrived'
+                            ),
+                            contents,
+                            image: '',
+                            useSound: [
+                              NotificationMethod.Sound,
+                              NotificationMethod.SoundAndAlert
+                            ].some(
+                              n =>
+                                n === appUserInfo.settings.notification.method
+                            )
+                              ? true
+                              : false,
+                            displayTime:
+                              appUserInfo.settings.notification
+                                .alertExposureTime * 1000
+                          };
+                          this.nativeService.notify(notiReq);
+                        }
                       }
                     }
                   }