diff --git a/src/gui/kima2.cpp b/src/gui/kima2.cpp
index b8886cf..f286e66 100644
--- a/src/gui/kima2.cpp
+++ b/src/gui/kima2.cpp
@@ -2,36 +2,28 @@
 
 #include "settingsdialog.h"
 #include <QApplication>
+#include <QDir>
+#include <QLibraryInfo>
 #include <QMessageBox>
 #include <QSettings>
 #include <QTranslator>
-#include <QLibraryInfo>
-#include <QDir>
 
 int main(int argc, char* argv[])
 {
-    // Q_INIT_RESOURCE(application);
-
-    // Set the locale to german, so that currency is correct
-    // std::locale german("de_DE.utf-8");
-    //std::locale myLocale("");
-    //std::locale::global(myLocale);
-
     QApplication kimaApp{argc, argv};
 
-    QCoreApplication::setOrganizationName("RustySoft");
+    // QCoreApplication::setOrganizationName("RustySoft");
     QCoreApplication::setOrganizationDomain("rustysoft.de");
-    QCoreApplication::setApplicationName("KIMA2");
+    QCoreApplication::setApplicationName("kima2");
 
     QTranslator qTranslator;
     QLocale german(QLocale::German);
 #ifdef __linux__
-    qTranslator.load("qt_" + german.name(),
-                      QLibraryInfo::location(QLibraryInfo::TranslationsPath));
+    qTranslator.load("qt_" + german.name(), QLibraryInfo::location(QLibraryInfo::TranslationsPath));
 #endif
 #ifdef _WIN32
     qTranslator.load("qt_" + german.name(),
-                      QApplication::applicationDirPath() + QDir::separator() + "translations");
+                     QApplication::applicationDirPath() + QDir::separator() + "translations");
 #endif
     kimaApp.installTranslator(&qTranslator);
 
diff --git a/src/gui/mainwindow.cpp b/src/gui/mainwindow.cpp
index 261774c..e3115d8 100644
--- a/src/gui/mainwindow.cpp
+++ b/src/gui/mainwindow.cpp
@@ -18,6 +18,8 @@
 #include <QFileDialog>
 #include <QMessageBox>
 #include <QSettings>
+#include <QStandardPaths>
+#include <QtGui/QDesktopServices>
 
 constexpr int STATUSBAR_TIMEOUT = 5000;
 
@@ -55,6 +57,14 @@ MainWindow::MainWindow()
             &MainWindow::onCancelAllArticlesButtonClicked);
     connect(ui_.aboutQtAction, &QAction::triggered, this, &MainWindow::onAboutQt);
     connect(ui_.aboutAction, &QAction::triggered, this, &MainWindow::onAbout);
+    connect(ui_.openManualAction, &QAction::triggered, this, []() {
+        auto locations = QStandardPaths::standardLocations(QStandardPaths::DataLocation);
+        for (auto location : locations) {
+            if (QFile::exists(location + QString("/Benutzerhandbuch.pdf"))) {
+                QDesktopServices::openUrl(location + QString("/Benutzerhandbuch.pdf"));
+            }
+        }
+    });
     connect(ui_.reportAction, &QAction::triggered, this, [=]() { ReportDialog(this).exec(); });
     connect(ui_.configAction, &QAction::triggered, this, [=]() {
         int result = SettingsDialog(this).exec();
diff --git a/src/gui/mainwindow.ui b/src/gui/mainwindow.ui
index 460b1bc..4171501 100644
--- a/src/gui/mainwindow.ui
+++ b/src/gui/mainwindow.ui
@@ -420,6 +420,7 @@ drucken</string>
     </property>
     <addaction name="aboutAction"/>
     <addaction name="aboutQtAction"/>
+    <addaction name="openManualAction"/>
    </widget>
    <widget class="QMenu" name="menuSales">
     <property name="title">
@@ -494,6 +495,11 @@ drucken</string>
     <string>Importieren von anderer Kasse (JSON)</string>
    </property>
   </action>
+  <action name="openManualAction">
+   <property name="text">
+    <string>Handbuch</string>
+   </property>
+  </action>
  </widget>
  <resources/>
  <connections/>
diff --git a/src/gui/settingsdialog.cpp b/src/gui/settingsdialog.cpp
index bc882b2..b14622a 100644
--- a/src/gui/settingsdialog.cpp
+++ b/src/gui/settingsdialog.cpp
@@ -20,7 +20,8 @@ SettingsDialog::SettingsDialog(QWidget* parent, Qt::WindowFlags f) : QDialog(par
     int feeInPercent = settings.value("global/feeInPercent").toInt();
     int maxFeeInEuro = settings.value("global/maxFeeInEuro").toInt();
 
-    market_ = dynamic_cast<MainWindow*>(parent)->getMarketplace();
+    if (parent)
+        market_ = dynamic_cast<MainWindow*>(parent)->getMarketplace();
 
     ui_.cashPointNoSpinBox->setValue(cashPointNo);
     // ui_.posPrinterDeviceEdit->setText(posPrinterDevice);
@@ -61,7 +62,7 @@ void SettingsDialog::accept()
 
     if (oldCashPointNo != newCashPointNo) {
         int result{0};
-        if (market_->getSales().size() > 0) {
+        if (market_ && market_->getSales().size() > 0) {
             result = QMessageBox(QMessageBox::Icon::Question, "Sind Sie sicher?",
                                  "Möchten Sie die Kassen-Nr wirklich ändern? Diese muss über alle "
                                  "Installationen hinweg eindeutig sein.",