diff --git a/kcms/componentchooser/componentchooser.h b/kcms/componentchooser/componentchooser.h
--- a/kcms/componentchooser/componentchooser.h
+++ b/kcms/componentchooser/componentchooser.h
@@ -35,9 +35,10 @@
 	virtual ~CfgPlugin(){}
 	virtual void load(KConfig *cfg)=0;
     virtual void save(KConfig *cfg)=0;
+
     bool hasChanged() const
     {
-        return m_currentIndex != -1 && m_currentIndex != currentIndex();
+        return count() > 1 && m_currentIndex != currentIndex();
     }
 
     void defaults()
@@ -47,6 +48,14 @@
         }
     }
 
+    int validLastCurrentIndex() const
+    {
+        // m_currentIndex == -1 means there are no previously saved value
+        // or maybe there were no choices in the combobox
+        // return 0 in those cases
+        return m_currentIndex == -1 ? 0 : m_currentIndex;
+    }
+
     bool isDefaults() const
     {
         return m_defaultIndex == -1 || m_defaultIndex == currentIndex();
diff --git a/kcms/componentchooser/componentchooserbrowser.cpp b/kcms/componentchooser/componentchooserbrowser.cpp
--- a/kcms/componentchooser/componentchooserbrowser.cpp
+++ b/kcms/componentchooser/componentchooserbrowser.cpp
@@ -41,7 +41,7 @@
         KOpenWithDialog dlg(QStringLiteral("x-scheme-handler/http"), QString(), this);
         dlg.setSaveNewApplications(true);
         if (dlg.exec() != QDialog::Accepted) {
-            setCurrentIndex(m_currentIndex);
+            setCurrentIndex(validLastCurrentIndex());
             return;
         }
 
@@ -104,6 +104,11 @@
 
 void CfgBrowser::save(KConfig *)
 {
+    if (currentIndex() == count() - 1) {
+        // no browser installed, nor selected
+        return;
+    }
+
     const QString browserStorageId = currentData().toString();
 
     BrowserSettings settings;
diff --git a/kcms/componentchooser/componentchooseremail.cpp b/kcms/componentchooser/componentchooseremail.cpp
--- a/kcms/componentchooser/componentchooseremail.cpp
+++ b/kcms/componentchooser/componentchooseremail.cpp
@@ -117,7 +117,7 @@
 
         if (dlg.exec() != QDialog::Accepted) {
             // restore previous setting
-            setCurrentIndex(m_currentIndex);
+            setCurrentIndex(validLastCurrentIndex());
             emit changed(false);
         } else {
             const auto service = dlg.service();
@@ -138,8 +138,17 @@
 
 void CfgEmailClient::save(KConfig *)
 {
+    if (currentIndex() == count() - 1) {
+        // no email client installed, nor selected
+        return;
+    }
+
     const QString &storageId = currentData().toString();
     const KService::Ptr emailClientService = KService::serviceByStorageId(storageId);
+    if (!emailClientService) {
+        // double checking, the selected email client might have been removed
+        return;
+    }
 
     const bool kmailSelected = m_defaultIndex != -1 && currentIndex() == m_defaultIndex;
     if (kmailSelected) {
@@ -152,7 +161,7 @@
 
     // Save the default email client in mimeapps.list
     KSharedConfig::Ptr profile = KSharedConfig::openConfig(QStringLiteral("mimeapps.list"), KConfig::NoGlobals, QStandardPaths::GenericConfigLocation);
-    if (profile->isConfigWritable(true) && emailClientService) {
+    if (profile->isConfigWritable(true)) {
 
         KSharedConfig::Ptr profile = KSharedConfig::openConfig(QStringLiteral("mimeapps.list"), KConfig::NoGlobals, QStandardPaths::GenericConfigLocation);
 
diff --git a/kcms/componentchooser/componentchooserfilemanager.cpp b/kcms/componentchooser/componentchooserfilemanager.cpp
--- a/kcms/componentchooser/componentchooserfilemanager.cpp
+++ b/kcms/componentchooser/componentchooserfilemanager.cpp
@@ -44,7 +44,7 @@
         KOpenWithDialog dlg({}, i18n("Select preferred file manager:"), QString(), this);
         dlg.setSaveNewApplications(true);
         if (dlg.exec() != QDialog::Accepted) {
-            setCurrentIndex(m_currentIndex);
+            setCurrentIndex(validLastCurrentIndex());
             return;
         }
 
@@ -113,26 +113,29 @@
 
 void CfgFileManager::save(KConfig *)
 {
+    if (currentIndex() == count() - 1) {
+        // no filemanager installed, nor selected
+        return;
+    }
+
     const QString storageId = currentData().toString();
-    if (!storageId.isEmpty()) {
-        m_currentIndex = currentIndex();
+    m_currentIndex = currentIndex();
 
-        // This is taken from filetypes/mimetypedata.cpp
-        KSharedConfig::Ptr profile = KSharedConfig::openConfig(QStringLiteral("mimeapps.list"), KConfig::NoGlobals, QStandardPaths::GenericConfigLocation);
-        if (!profile->isConfigWritable(true)) // warn user if mimeapps.list is root-owned (#155126/#94504)
-            return;
-        KConfigGroup addedApps(profile, s_AddedAssociations);
-        QStringList userApps = addedApps.readXdgListEntry(mime);
-        userApps.removeAll(storageId); // remove if present, to make it first in the list
-        userApps.prepend(storageId);
-        addedApps.writeXdgListEntry(mime, userApps);
+    // This is taken from filetypes/mimetypedata.cpp
+    KSharedConfig::Ptr profile = KSharedConfig::openConfig(QStringLiteral("mimeapps.list"), KConfig::NoGlobals, QStandardPaths::GenericConfigLocation);
+    if (!profile->isConfigWritable(true)) // warn user if mimeapps.list is root-owned (#155126/#94504)
+        return;
+    KConfigGroup addedApps(profile, s_AddedAssociations);
+    QStringList userApps = addedApps.readXdgListEntry(mime);
+    userApps.removeAll(storageId); // remove if present, to make it first in the list
+    userApps.prepend(storageId);
+    addedApps.writeXdgListEntry(mime, userApps);
 
-        // Save the default file manager as per mime-apps spec 1.0.1
-        KConfigGroup defaultApp(profile, s_DefaultApplications);
-        defaultApp.writeXdgListEntry(mime, QStringList(storageId));
+    // Save the default file manager as per mime-apps spec 1.0.1
+    KConfigGroup defaultApp(profile, s_DefaultApplications);
+    defaultApp.writeXdgListEntry(mime, QStringList(storageId));
 
-        profile->sync();
+    profile->sync();
 
-        emit changed(false);
-    }
+    emit changed(false);
 }
diff --git a/kcms/componentchooser/componentchooserterminal.cpp b/kcms/componentchooser/componentchooserterminal.cpp
--- a/kcms/componentchooser/componentchooserterminal.cpp
+++ b/kcms/componentchooser/componentchooserterminal.cpp
@@ -84,21 +84,25 @@
     // add a other option to add a new terminal emulator with KOpenWithDialog
     addItem(QIcon::fromTheme(QStringLiteral("application-x-shellscript")), i18n("Other..."), QStringLiteral());
 
-	emit changed(false);
+    emit changed(false);
 }
 
 void CfgTerminalEmulator::save(KConfig *)
 {
+    if (currentIndex() == count() - 1) {
+        // no terminal installed, nor selected
+        return;
+    }
+
     const QString terminal = currentData().toString();
-    m_currentIndex = currentIndex();
 
-	TerminalSettings settings;
+    TerminalSettings settings;
     settings.setTerminalApplication(terminal);
-	settings.save();
+    settings.save();
 
     m_currentIndex = currentIndex();
 
-	QDBusMessage message  = QDBusMessage::createMethodCall(QStringLiteral("org.kde.klauncher5"),
+    QDBusMessage message  = QDBusMessage::createMethodCall(QStringLiteral("org.kde.klauncher5"),
                                                            QStringLiteral("/KLauncher"),
                                                            QStringLiteral("org.kde.KLauncher"),
                                                            QStringLiteral("reparseConfiguration"));
@@ -114,7 +118,7 @@
     dlg.hideRunInTerminal();
     dlg.setSaveNewApplications(true);
     if (dlg.exec() != QDialog::Accepted) {
-        setCurrentIndex(m_currentIndex);
+        setCurrentIndex(validLastCurrentIndex());
         return;
     }
     const auto service = dlg.service();