diff --git a/RedPandaIDE/mainwindow.cpp b/RedPandaIDE/mainwindow.cpp
index ea15177f..caafd093 100644
--- a/RedPandaIDE/mainwindow.cpp
+++ b/RedPandaIDE/mainwindow.cpp
@@ -999,32 +999,35 @@ void MainWindow::applySettings()
         themeManager.prepareCustomeTheme();
     }
     themeManager.setUseCustomTheme(pSettings->environment().useCustomTheme());
+    PAppTheme appTheme;
     try {
-        PAppTheme appTheme = themeManager.theme(pSettings->environment().theme());
-        const QString& style = appTheme->style();
-        if (style == "RedPandaDarkFusion")
-            QApplication::setStyle(new DarkFusionStyle());//app takes the onwership
-        else if (style == "RedPandaLightFusion")
-            QApplication::setStyle(new LightFusionStyle());//app takes the onwership
-        else
-            QApplication::setStyle(style);
-        qApp->setPalette(appTheme->palette());
-        //fix for qstatusbar bug
-        mFileEncodingStatus->setPalette(appTheme->palette());
-        mFileModeStatus->setPalette(appTheme->palette());
-        mFileInfoStatus->setPalette(appTheme->palette());
+        appTheme = themeManager.theme(pSettings->environment().theme());
     } catch (FileError e) {
         QMessageBox::critical(this,
                               tr("Load Theme Error"),
                               e.reason());
+        appTheme = AppTheme::fallbackTheme();
     }
 #ifdef ENABLE_LUA_ADDON
     catch (AddOn::LuaError e) {
         QMessageBox::critical(this,
                               tr("Load Theme Error"),
                               e.reason());
+        appTheme = AppTheme::fallbackTheme();
     }
 #endif
+    const QString& style = appTheme->style();
+    if (style == "RedPandaDarkFusion")
+        QApplication::setStyle(new DarkFusionStyle());//app takes the onwership
+    else if (style == "RedPandaLightFusion")
+        QApplication::setStyle(new LightFusionStyle());//app takes the onwership
+    else
+        QApplication::setStyle(style);
+    qApp->setPalette(appTheme->palette());
+    //fix for qstatusbar bug
+    mFileEncodingStatus->setPalette(appTheme->palette());
+    mFileModeStatus->setPalette(appTheme->palette());
+    mFileInfoStatus->setPalette(appTheme->palette());
 
     updateEditorColorSchemes();
 
diff --git a/RedPandaIDE/thememanager.cpp b/RedPandaIDE/thememanager.cpp
index baaa7c5d..22f00ce3 100644
--- a/RedPandaIDE/thememanager.cpp
+++ b/RedPandaIDE/thememanager.cpp
@@ -119,6 +119,8 @@ QList<PAppTheme> ThemeManager::getThemes()
     std::sort(result.begin(),result.end(),[](const PAppTheme &theme1, const PAppTheme &theme2){
         return QFileInfo(theme1->filename()).baseName() <  QFileInfo(theme2->filename()).baseName();
     });
+    if (result.isEmpty())
+        result.append(AppTheme::fallbackTheme());
     return result;
 }
 
@@ -347,3 +349,18 @@ const QString &AppTheme::style() const
 {
     return mStyle;
 }
+
+AppTheme::AppTheme() :
+    mName("__failsafe__theme__"),
+    mDisplayName("Fusion [fail-safe hard-coded]"),
+    mStyle("fusion"),
+    mDefaultColorScheme("Adaptive"),
+    mDefaultIconSet("newlook")
+{
+}
+
+PAppTheme AppTheme::fallbackTheme()
+{
+    static PAppTheme theme = PAppTheme(new AppTheme());
+    return theme;
+}
diff --git a/RedPandaIDE/thememanager.h b/RedPandaIDE/thememanager.h
index 41bd591a..279b5fb7 100644
--- a/RedPandaIDE/thememanager.h
+++ b/RedPandaIDE/thememanager.h
@@ -22,6 +22,9 @@
 #include <memory>
 #include <QObject>
 
+class AppTheme;
+using PAppTheme = std::shared_ptr<AppTheme>;
+
 class AppTheme : public QObject{
     Q_OBJECT
 public:
@@ -102,6 +105,12 @@ public:
 
     const QString& filename() const;
 
+public:
+    static PAppTheme fallbackTheme();
+
+private:
+    AppTheme();
+
 private:
     static QPalette initialPalette();
 private:
@@ -114,8 +123,6 @@ private:
     QString mFilename;
 };
 
-using PAppTheme = std::shared_ptr<AppTheme>;
-
 class ThemeManager : public QObject
 {
     Q_OBJECT