diff --git a/content/en/mobile_application/README.md b/content/en/mobile_application/README.md
index addbd9e..913c1f3 100644
--- a/content/en/mobile_application/README.md
+++ b/content/en/mobile_application/README.md
@@ -7,7 +7,7 @@ Please click [here](https://play.google.com/store/apps/details?id=com.mediatek.i
 
 <a href="https://play.google.com/store/apps/details?id=com.mediatek.iotcloud"><img src="https://developer.android.com/images/brand/en_app_rgb_wo_60.png" border="0"></a>
 
-(If you already installed previous version, you need to un-install the previous version and install the new version again.)
+**(Please be noted that due to system upgrade to enhace security, the old version of mobile app is not working anymore. Please download the latest version of the mobile app in the Google play store to continue using our MCS mobile app.)**
 
 ![](../images/mobileapp_android.png)
 
@@ -15,7 +15,6 @@ The mobile app currently offers for Android only.
 
 To install the app, you must have android v4.0 or above version, and open the above download link in your mobile browser
 
-**Please note: Android 5.x is currently not supported, we will have a refresh shortly. **
 
 Once installed at first launch you will see the screen below:
 
diff --git a/content/zh-CN/mobile_application/README.md b/content/zh-CN/mobile_application/README.md
index fcf63d8..7fe408c 100644
--- a/content/zh-CN/mobile_application/README.md
+++ b/content/zh-CN/mobile_application/README.md
@@ -5,7 +5,7 @@
 
 <a href="https://play.google.com/store/apps/details?id=com.mediatek.iotcloud"><img src="https://developer.android.com/images/brand/en_app_rgb_wo_60.png" border="0"></a>
 
-(请注意，若您已经安装过旧的版本，且欲安装新版，请先移除旧版再行安装新版本)
+**(请注意：为了增加效能和安全性，我们将系统全面升级。旧版本的手机应用程式将不再能使用，请于Google play 商店下载最新版本的手机应用程式来连结您的手机与MCS平台)**
 
 ![](../images/mobileapp_android.png)
 
diff --git a/content/zh-TW/mobile_application/README.md b/content/zh-TW/mobile_application/README.md
index e56a066..4791bfe 100644
--- a/content/zh-TW/mobile_application/README.md
+++ b/content/zh-TW/mobile_application/README.md
@@ -5,7 +5,7 @@
 
 <a href="https://play.google.com/store/apps/details?id=com.mediatek.iotcloud"><img src="https://developer.android.com/images/brand/en_app_rgb_wo_60.png" border="0"></a>
 
-(請注意，若您已經安裝過舊的版本，且欲安裝新版，請先移除舊版再行安裝新版本)
+**(請注意：為了增加效能和安全性，我們將系統全面升級。舊版本的手機應用程式將不再能使用，請於Google play 商店下載最新版本的手機應用程式來連結您的手機與MCS平台)**
 
 ![](../images/mobileapp_android.png)