diff -Nru ukui-session-manager-3.0.4/debian/changelog ukui-session-manager-3.0.5/debian/changelog
--- ukui-session-manager-3.0.4/debian/changelog	2021-08-05 07:45:20.000000000 +0000
+++ ukui-session-manager-3.0.5/debian/changelog	2021-09-30 07:16:58.000000000 +0000
@@ -1,3 +1,9 @@
+ukui-session-manager (3.0.5-1) unstable; urgency=medium
+
+  * New upstream bugfix release. (LP: #1945570)
+
+ -- handsome_feng <jianfengli@ubuntukylin.com>  Thu, 30 Sep 2021 15:16:58 +0800
+
 ukui-session-manager (3.0.4-1) unstable; urgency=medium
 
   * New upstream release.
diff -Nru ukui-session-manager-3.0.4/tools/main.cpp ukui-session-manager-3.0.5/tools/main.cpp
--- ukui-session-manager-3.0.4/tools/main.cpp	2021-08-18 08:47:37.000000000 +0000
+++ ukui-session-manager-3.0.5/tools/main.cpp	2021-09-30 07:41:14.000000000 +0000
@@ -141,7 +141,7 @@
         }
         file_backup.close();
         if (flock(fd_backup, LOCK_UN) == 0) {
-            qDebug() << "unlock sucess.";
+            qDebug() << "unlock success.";
         } else {
             qDebug() << "unlock fail.";
         }
@@ -159,7 +159,7 @@
         }
         file_backup.close();
         if (flock(fd_update, LOCK_UN) == 0) {
-            qDebug() << "unlock sucess.";
+            qDebug() << "unlock success.";
         } else {
             qDebug() << "unlock fail.";
         }
diff -Nru ukui-session-manager-3.0.4/tools/powerprovider.cpp ukui-session-manager-3.0.5/tools/powerprovider.cpp
--- ukui-session-manager-3.0.4/tools/powerprovider.cpp	2021-08-05 07:44:44.000000000 +0000
+++ ukui-session-manager-3.0.5/tools/powerprovider.cpp	2021-09-30 07:41:53.000000000 +0000
@@ -105,7 +105,7 @@
     msgBox.setIcon(QMessageBox::Warning);
     msgBox.setWindowFlags(Qt::WindowStaysOnTopHint);
     //    msgBox.setModal(false);
-    msgBox.setText(QObject::tr("some applications are running and they dont want you to do this."));
+    msgBox.setText(QObject::tr("some applications are running and they don't want you to do this."));
     QPushButton *stillButton =
         msgBox.addButton(QObject::tr("Still to do!"), QMessageBox::ActionRole);
     QPushButton *giveupButton = msgBox.addButton(QObject::tr("give up"), QMessageBox::RejectRole);
diff -Nru ukui-session-manager-3.0.4/translations/zh_CN.ts ukui-session-manager-3.0.5/translations/zh_CN.ts
--- ukui-session-manager-3.0.4/translations/zh_CN.ts	2021-08-18 08:30:14.000000000 +0000
+++ ukui-session-manager-3.0.5/translations/zh_CN.ts	2021-09-30 07:42:05.000000000 +0000
@@ -161,7 +161,7 @@
     </message>
     <message>
         <location filename="../tools/powerprovider.cpp" line="107"/>
-        <source>some applications are running and they dont want you to do this.</source>
+        <source>some applications are running and they don't want you to do this.</source>
         <translation>一些程序正在运行，而且它不希望你继续该操作。</translation>
     </message>
     <message>
diff -Nru ukui-session-manager-3.0.4/ukui-session/main.cpp ukui-session-manager-3.0.5/ukui-session/main.cpp
--- ukui-session-manager-3.0.4/ukui-session/main.cpp	2021-08-18 08:47:37.000000000 +0000
+++ ukui-session-manager-3.0.5/ukui-session/main.cpp	2021-09-30 08:07:08.000000000 +0000
@@ -185,7 +185,7 @@
 {
     qInstallMessageHandler(myMessageOutput);
     //initUkuiLog4qt("ukui-session");
-    qDebug() << "UKUI session manager start.";
+    qDebug() << "---------------------------------------------------------UKUI session manager start.---------------------------------------------------------";
     SessionApplication app(argc, argv);
 
     Set4KScreenScale();
diff -Nru ukui-session-manager-3.0.4/ukui-session/modulemanager.cpp ukui-session-manager-3.0.5/ukui-session/modulemanager.cpp
--- ukui-session-manager-3.0.4/ukui-session/modulemanager.cpp	2021-08-18 08:47:46.000000000 +0000
+++ ukui-session-manager-3.0.5/ukui-session/modulemanager.cpp	2021-09-30 08:07:08.000000000 +0000
@@ -86,7 +86,8 @@
       isPanelStarted(false),
       isDesktopStarted(false),
       isWMStarted(false),
-      isCompsiteStarted(false)
+      isCompsiteStarted(false),
+      m_ukuiKwinExisted(false)
 {
     /*const QFile file_installer("/etc/xdg/autostart/kylin-os-installer.desktop");
     if(file_installer.exists()){
@@ -135,16 +136,17 @@
     QString file_manager;
     QString wm_notfound;
     if (QGSettings::isSchemaInstalled(id)) {
-        const QGSettings* gs = new QGSettings(SESSION_REQUIRED_COMPONENTS,SESSION_REQUIRED_COMPONENTS_PATH,this);
+        const QGSettings *gs = new QGSettings(SESSION_REQUIRED_COMPONENTS,SESSION_REQUIRED_COMPONENTS_PATH,this);
         if(gs == NULL){
             qDebug()<<"QGSettings init error";
-            free(&gs);
             return;
         }
         window_manager = gs->get("windowmanager").toString() + ".desktop";
         panel = gs->get("panel").toString() + ".desktop";
         file_manager = gs->get("filemanager").toString() + ".desktop";
         wm_notfound = gs->get("windowmanager").toString();
+
+        delete gs;
     } else {
         //gsetting安装失败，或无法获取，设置默认值
         qDebug() << "从gsettings 中或取值失败，设置默认值";
@@ -193,16 +195,35 @@
     if (wm_found == false) {
         QFileInfo check_ukwm("/usr/share/applications/ukwm.desktop");
         QFileInfo check_ukuikwin("/usr/share/applications/ukui-kwin.desktop");
-        if(check_ukwm.exists()) {
-            window_manager = "ukwm.desktop";
-            mWindowManager.load("/usr/share/applications/ukwm.desktop");
-        }else if(check_ukuikwin.exists()) {
+        if (check_ukuikwin.exists()) {
             window_manager = "ukui-kwin.desktop";
             mWindowManager.load("/usr/share/applications/ukui-kwin.desktop");
+        } else if (check_ukwm.exists()) {
+            window_manager = "ukwm.desktop";
+            mWindowManager.load("/usr/share/applications/ukwm.desktop");
+        } else {
+            qDebug() << "No WindowManager founded.";
+            return;
         }
         wm_found = true;
     }
 
+    QString wmFilePath = mWindowManager.fileName();
+    if (!wmFilePath.isEmpty()) {
+        int pos = wmFilePath.lastIndexOf ("/");
+        QString fileName = wmFilePath.right(wmFilePath.length() - pos - 1);
+        if (fileName == "ukui-kwin.desktop") {
+            qDebug() << "ukuikwin exist on this machine";
+            m_ukuiKwinExisted = true;
+        } else {
+            qDebug() << "ukwm exist on this machine";
+            m_ukuiKwinExisted = false;
+        }
+    } else if (wmFilePath.isEmpty()) {
+        qDebug() << "No WindowManager loaded.";
+        return;
+    }
+
     //配置文件所给的窗口管理器找不到.desktop文件时，将所给QString设为可执行命令，创建一个desktop文件赋给mWindowManager
 //    if (wm_found == false) {
 //        mWindowManager = XdgDesktopFile(XdgDesktopFile::ApplicationType,"window-manager", wm_notfound);
@@ -318,20 +339,23 @@
 
 void ModuleManager::startCompsite(){
     qDebug() << "Enter:: startCompsite";
-    if(!isPanelStarted || !isDesktopStarted || !isWMStarted) return;
 
-    if(isCompsiteStarted) return;
-    isCompsiteStarted = true;
+    if (m_ukuiKwinExisted) {
+        if (!isPanelStarted || !isDesktopStarted || !isWMStarted) return;
 
-    // start composite
-    QDBusInterface dbus("org.ukui.KWin", "/Compositor", "org.ukui.kwin.Compositing", QDBusConnection::sessionBus());
+        if (isCompsiteStarted) return;
+        isCompsiteStarted = true;
 
-    if (!dbus.isValid()) {
-        qWarning() << "dbusCall: QDBusInterface is invalid";
-        return;
+        // start composite
+        QDBusInterface dbus("org.ukui.KWin", "/Compositor", "org.ukui.kwin.Compositing", QDBusConnection::sessionBus());
+
+        if (!dbus.isValid()) {
+            qWarning() << "dbusCall: QDBusInterface is invalid";
+            return;
+        }
+        qDebug() << "Start composite";
+        dbus.call("resume");
     }
-    qDebug() << "Start composite";
-    dbus.call("resume");
 
     timerUpdate();
 }
diff -Nru ukui-session-manager-3.0.4/ukui-session/modulemanager.h ukui-session-manager-3.0.5/ukui-session/modulemanager.h
--- ukui-session-manager-3.0.4/ukui-session/modulemanager.h	2021-08-18 08:47:46.000000000 +0000
+++ ukui-session-manager-3.0.5/ukui-session/modulemanager.h	2021-09-30 08:07:08.000000000 +0000
@@ -105,6 +105,7 @@
 
     bool mWmStarted;
     bool mTrayStarted;
+    bool m_ukuiKwinExisted;
     QEventLoop* mWaitLoop;
 
     XdgDesktopFileList mInitialization;
diff -Nru ukui-session-manager-3.0.4/ukui-session/usminhibit.cpp ukui-session-manager-3.0.5/ukui-session/usminhibit.cpp
--- ukui-session-manager-3.0.4/ukui-session/usminhibit.cpp	2021-08-05 07:44:44.000000000 +0000
+++ ukui-session-manager-3.0.5/ukui-session/usminhibit.cpp	2021-09-30 07:42:16.000000000 +0000
@@ -141,7 +141,7 @@
 
 QStringList usminhibit::getinhibitor(){
     //do not show inhibitorName to user
-    //in case we dont know who is inhibiting
+    //in case we don't know who is inhibiting
     QHashIterator<quint32, inhibit> i(hash);
     QStringList inhibitors;
     while (i.hasNext()) {