diff --git a/crdesigner/common/config/config_base.py b/crdesigner/common/config/config_base.py
index 9f151b80..6f093562 100644
--- a/crdesigner/common/config/config_base.py
+++ b/crdesigner/common/config/config_base.py
@@ -4,7 +4,15 @@
 
 import yaml
 from PyQt6.QtCore import QObject, pyqtSignal
-from PyQt6.QtWidgets import QMessageBox
+
+try:
+    # required for Ubuntu 20.04 since there a system library is too old for pyqt6 and the import fails
+    # when not importing this, one can still use the map conversion
+    from PyQt6.QtWidgets import QMessageBox
+
+    pyqt_available = True
+except (ImportError, RuntimeError):
+    pyqt_available = False
 
 from crdesigner.ui.gui.utilities.custom_yaml import add_custom_interval_interpreter
 
@@ -136,15 +144,16 @@ def restore_last_value(self):
         self.value = copy.deepcopy(self.last_saved)
 
     def _warning_wrong_setting(self):
-        warning_dialog = QMessageBox()
-        warning_dialog.warning(
-            None,
-            "Warning",
-            f"Setting {self.display_name} contains invalid value!",
-            QMessageBox.StandardButton.Ok,
-            QMessageBox.StandardButton.Ok,
-        )
-        warning_dialog.close()
+        if pyqt_available:
+            warning_dialog = QMessageBox()
+            warning_dialog.warning(
+                None,
+                "Warning",
+                f"Setting {self.display_name} contains invalid value!",
+                QMessageBox.StandardButton.Ok,
+                QMessageBox.StandardButton.Ok,
+            )
+            warning_dialog.close()
         self.reset()
 
 
diff --git a/crdesigner/common/sumo_available.py b/crdesigner/common/sumo_available.py
new file mode 100644
index 00000000..82a2671a
--- /dev/null
+++ b/crdesigner/common/sumo_available.py
@@ -0,0 +1,17 @@
+from crdesigner.common import logging
+
+try:
+    from sumocr.interface.sumo_simulation import SumoSimulation  # noqa: F401
+
+    from crdesigner.map_conversion.sumo_map.config import SumoConfig  # noqa: F401
+    from crdesigner.map_conversion.sumo_map.cr2sumo.converter import (  # noqa: F401
+        CR2SumoMapConverter,
+    )
+
+    SUMO_AVAILABLE = True
+except ImportError:
+    logging.warning(
+        "Cannot import SUMO. SUMO simulation will not be offered in Scenario Designer GUI. "
+        "The GUI and other map conversions should work."
+    )
+    SUMO_AVAILABLE = False
diff --git a/crdesigner/map_conversion/map_conversion_interface.py b/crdesigner/map_conversion/map_conversion_interface.py
index 2d40a222..2613dbf8 100644
--- a/crdesigner/map_conversion/map_conversion_interface.py
+++ b/crdesigner/map_conversion/map_conversion_interface.py
@@ -12,12 +12,12 @@
 from crdesigner.common.config.lanelet2_config import lanelet2_config
 from crdesigner.common.config.opendrive_config import open_drive_config
 from crdesigner.common.file_reader import CRDesignerFileReader
+from crdesigner.common.sumo_available import SUMO_AVAILABLE
 from crdesigner.map_conversion.lanelet2.cr2lanelet import CR2LaneletConverter
 from crdesigner.map_conversion.lanelet2.lanelet2_parser import Lanelet2Parser
 from crdesigner.map_conversion.lanelet2.lanelet2cr import Lanelet2CRConverter
 from crdesigner.map_conversion.opendrive.opendrive_conversion.network import Network
 from crdesigner.map_conversion.opendrive.opendrive_parser.parser import parse_opendrive
-from crdesigner.ui.gui.utilities.gui_sumo_simulation import SUMO_AVAILABLE
 
 if SUMO_AVAILABLE:
     from crdesigner.map_conversion.sumo_map.config import SumoConfig
diff --git a/crdesigner/map_conversion/sumo_map/sumo2cr.py b/crdesigner/map_conversion/sumo_map/sumo2cr.py
index cd7ba56d..ece319c6 100644
--- a/crdesigner/map_conversion/sumo_map/sumo2cr.py
+++ b/crdesigner/map_conversion/sumo_map/sumo2cr.py
@@ -3,7 +3,15 @@
 
 from commonroad.scenario.scenario import Scenario
 from lxml import etree
-from PyQt6.QtWidgets import QMessageBox
+
+try:
+    # required for Ubuntu 20.04 since there a system library is too old for pyqt6 and the import fails
+    # when not importing this, one can still use the map conversion
+    from PyQt6.QtWidgets import QMessageBox
+
+    pyqt_available = True
+except (ImportError, RuntimeError):
+    pyqt_available = False
 
 from crdesigner.map_conversion.opendrive.opendrive_conversion.network import Network
 from crdesigner.map_conversion.opendrive.opendrive_parser.parser import parse_opendrive
@@ -18,8 +26,8 @@ def convert_net_to_cr(net_file: str, verbose: bool = False) -> Scenario:
 
     :return: commonroad map file
     """
-    if net_file is None:
-        QMessageBox.warning(None, "Warning", "No file selected.", QMessageBox.Ok)
+    if net_file is None and pyqt_available:
+        QMessageBox.warning(None, "Warning", "No file selected.", QMessageBox.StandardButton.Ok)
         return
     assert isinstance(net_file, str)
 
diff --git a/crdesigner/ui/gui/controller/animated_viewer/animated_viewer_controller.py b/crdesigner/ui/gui/controller/animated_viewer/animated_viewer_controller.py
index 7ea2a802..59378c64 100644
--- a/crdesigner/ui/gui/controller/animated_viewer/animated_viewer_controller.py
+++ b/crdesigner/ui/gui/controller/animated_viewer/animated_viewer_controller.py
@@ -6,11 +6,11 @@
 from PyQt6.QtWidgets import QFileDialog, QMessageBox
 
 from crdesigner.common.config.gui_config import gui_config
+from crdesigner.common.sumo_available import SUMO_AVAILABLE
 from crdesigner.ui.gui.controller.animated_viewer.dynamic_canvas_controller import (
     DynamicCanvasController,
 )
 from crdesigner.ui.gui.model.planning_problem_set_model import PlanningProblemSetModel
-from crdesigner.ui.gui.utilities.gui_sumo_simulation import SUMO_AVAILABLE
 from crdesigner.ui.gui.utilities.helper import draw_lanelet_polygon
 
 if SUMO_AVAILABLE:
diff --git a/crdesigner/ui/gui/controller/mwindow_controller.py b/crdesigner/ui/gui/controller/mwindow_controller.py
index 2101a179..bfef2c03 100644
--- a/crdesigner/ui/gui/controller/mwindow_controller.py
+++ b/crdesigner/ui/gui/controller/mwindow_controller.py
@@ -8,6 +8,7 @@
 
 from crdesigner.common.config.gui_config import gui_config
 from crdesigner.common.logging import logger
+from crdesigner.common.sumo_available import SUMO_AVAILABLE
 from crdesigner.ui.gui.autosaves.autosaves_setup import DIR_AUTOSAVE
 from crdesigner.ui.gui.controller.animated_viewer.animated_viewer_wrapper_controller import (
     AnimatedViewerWrapperController,
@@ -32,7 +33,6 @@
 from crdesigner.ui.gui.model.planning_problem_set_model import PlanningProblemSetModel
 from crdesigner.ui.gui.model.scenario_model import ScenarioModel
 from crdesigner.ui.gui.utilities.file_actions import open_commonroad_file
-from crdesigner.ui.gui.utilities.gui_sumo_simulation import SUMO_AVAILABLE
 from crdesigner.ui.gui.utilities.util import (
     find_invalid_lanelet_polygons,
     find_invalid_ref_of_traffic_lights,
diff --git a/crdesigner/ui/gui/controller/toolboxes/converter_toolbox/map_conversion_controller.py b/crdesigner/ui/gui/controller/toolboxes/converter_toolbox/map_conversion_controller.py
index 316780cd..c1c9adfb 100644
--- a/crdesigner/ui/gui/controller/toolboxes/converter_toolbox/map_conversion_controller.py
+++ b/crdesigner/ui/gui/controller/toolboxes/converter_toolbox/map_conversion_controller.py
@@ -8,6 +8,7 @@
 
 from crdesigner.common.config.osm_config import osm_config
 from crdesigner.common.logging import logger
+from crdesigner.common.sumo_available import SUMO_AVAILABLE
 from crdesigner.map_conversion.lanelet2.cr2lanelet import CR2LaneletConverter
 from crdesigner.map_conversion.lanelet2.lanelet2_parser import Lanelet2Parser
 from crdesigner.map_conversion.lanelet2.lanelet2cr import Lanelet2CRConverter
@@ -27,7 +28,6 @@
     download_around_map,
 )
 from crdesigner.ui.gui.model.scenario_model import ScenarioModel
-from crdesigner.ui.gui.utilities.gui_sumo_simulation import SUMO_AVAILABLE
 from crdesigner.ui.gui.utilities.util import select_local_file
 from crdesigner.ui.gui.utilities.waitingspinnerwidget import QtWaitingSpinner
 from crdesigner.ui.gui.view.toolboxes.converter_toolbox.converter_toolbox_ui import (
diff --git a/crdesigner/ui/gui/controller/toolboxes/road_network_toolbox/aerial_image_controller.py b/crdesigner/ui/gui/controller/toolboxes/road_network_toolbox/aerial_image_controller.py
index aed5e985..15e26fd2 100644
--- a/crdesigner/ui/gui/controller/toolboxes/road_network_toolbox/aerial_image_controller.py
+++ b/crdesigner/ui/gui/controller/toolboxes/road_network_toolbox/aerial_image_controller.py
@@ -5,7 +5,15 @@
 from commonroad.scenario.scenario import Scenario
 from pyproj import CRS, Transformer
 from PyQt6.QtCore import Q_ARG, QMetaObject, QRunnable, Qt, QThreadPool
-from PyQt6.QtWidgets import QMessageBox
+
+try:
+    # required for Ubuntu 20.04 since there a system library is too old for pyqt6 and the import fails
+    # when not importing this, one can still use the map conversion
+    from PyQt6.QtWidgets import QMessageBox
+
+    pyqt_available = True
+except (ImportError, RuntimeError):
+    pyqt_available = False
 
 from crdesigner.common.config.gui_config import gui_config as config_settings
 from crdesigner.common.config.gui_config import lanelet2_default
@@ -149,7 +157,7 @@ def show_aerial_image(self, current_position: bool = False):
             return
 
         if self.road_network_toolbox_ui.bing_selection.isChecked():
-            if config_settings.BING_MAPS_KEY == "":
+            if config_settings.BING_MAPS_KEY == "" and pyqt_available:
                 print("_Warning__: No Bing Maps key specified. Go to settings and set password.")
                 warning_dialog = QMessageBox()
                 warning_dialog.warning(
diff --git a/crdesigner/ui/gui/controller/toolboxes/road_network_toolbox/traffic_lights_controller.py b/crdesigner/ui/gui/controller/toolboxes/road_network_toolbox/traffic_lights_controller.py
index 46651eb1..b1a8736e 100644
--- a/crdesigner/ui/gui/controller/toolboxes/road_network_toolbox/traffic_lights_controller.py
+++ b/crdesigner/ui/gui/controller/toolboxes/road_network_toolbox/traffic_lights_controller.py
@@ -10,8 +10,8 @@
 )
 
 from crdesigner.common.logging import logger
+from crdesigner.common.sumo_available import SUMO_AVAILABLE
 from crdesigner.ui.gui.model.scenario_model import ScenarioModel
-from crdesigner.ui.gui.utilities.gui_sumo_simulation import SUMO_AVAILABLE
 from crdesigner.ui.gui.view.toolboxes.road_network_toolbox.road_network_toolbox_ui.road_network_toolbox_ui import (
     RoadNetworkToolboxUI,
 )
diff --git a/crdesigner/ui/gui/utilities/errors.py b/crdesigner/ui/gui/utilities/errors.py
index 57900099..6f917056 100644
--- a/crdesigner/ui/gui/utilities/errors.py
+++ b/crdesigner/ui/gui/utilities/errors.py
@@ -1,28 +1,31 @@
-""" """
+try:
+    # required for Ubuntu 20.04 since there a system library is too old for pyqt6 and the import fails
+    # when not importing this, one can still use the map conversion
+    from PyQt6.QtWidgets import QMessageBox, QWidget
 
-from PyQt6.QtWidgets import QMessageBox, QWidget
+    pyqt_available = True
 
+    def _message(
+        widget: QWidget,
+        title: str,
+        text: str,
+        buttons=QMessageBox.StandardButton.Ok,
+        default_button=QMessageBox.StandardButton.Ok,
+    ) -> QMessageBox.StandardButton:
+        messagebox = QMessageBox()
+        reply = messagebox.warning(widget, title, text, buttons, default_button)
+        messagebox.close()
+        return reply
 
-def _message(
-    widget: QWidget,
-    title: str,
-    text: str,
-    buttons=QMessageBox.StandardButton.Ok,
-    default_button=QMessageBox.StandardButton.Ok,
-) -> QMessageBox.StandardButton:
-    messagebox = QMessageBox()
-    reply = messagebox.warning(widget, title, text, buttons, default_button)
-    messagebox.close()
-    return reply
+    def error(
+        widget: QWidget, text: str, buttons=QMessageBox.StandardButton.Ok, default_button=QMessageBox.StandardButton.Ok
+    ) -> QMessageBox.StandardButton:
+        return _message(widget, "Error", text, buttons, default_button)
 
+    def warning(
+        widget: QWidget, text: str, buttons=QMessageBox.StandardButton.Ok, default_button=QMessageBox.StandardButton.Ok
+    ) -> QMessageBox.StandardButton:
+        return _message(widget, "Warning", text, buttons, default_button)
 
-def error(
-    widget: QWidget, text: str, buttons=QMessageBox.StandardButton.Ok, default_button=QMessageBox.StandardButton.Ok
-) -> QMessageBox.StandardButton:
-    return _message(widget, "Error", text, buttons, default_button)
-
-
-def warning(
-    widget: QWidget, text: str, buttons=QMessageBox.StandardButton.Ok, default_button=QMessageBox.StandardButton.Ok
-) -> QMessageBox.StandardButton:
-    return _message(widget, "Warning", text, buttons, default_button)
+except (ImportError, RuntimeError):
+    pyqt_available = False
diff --git a/crdesigner/ui/gui/utilities/gui_sumo_simulation.py b/crdesigner/ui/gui/utilities/gui_sumo_simulation.py
index 806a34c4..af31a9c8 100644
--- a/crdesigner/ui/gui/utilities/gui_sumo_simulation.py
+++ b/crdesigner/ui/gui/utilities/gui_sumo_simulation.py
@@ -3,24 +3,15 @@
 
 from commonroad.scenario.scenario import Scenario
 
+from crdesigner.common.sumo_available import SUMO_AVAILABLE
 from crdesigner.ui.gui.utilities.errors import error
 from crdesigner.ui.gui.utilities.util import Observable
 
-# try to import sumo functionality
-try:
+if SUMO_AVAILABLE:
     from sumocr.interface.sumo_simulation import SumoSimulation
-
     from crdesigner.map_conversion.sumo_map.config import SumoConfig
     from crdesigner.map_conversion.sumo_map.cr2sumo.converter import CR2SumoMapConverter
 
-    SUMO_AVAILABLE = True
-except ImportError:
-    logging.warning(
-        "Cannot import SUMO. SUMO simulation will not be offered in Scenario Designer GUI. "
-        "The GUI and other map conversions should work."
-    )
-    SUMO_AVAILABLE = False
-
 from PyQt6 import QtWidgets
 from PyQt6.QtCore import QThread
 from PyQt6.QtWidgets import QFrame, QMessageBox
diff --git a/crdesigner/ui/gui/utilities/sumo_settings.py b/crdesigner/ui/gui/utilities/sumo_settings.py
index 2984f4d1..ce559a50 100644
--- a/crdesigner/ui/gui/utilities/sumo_settings.py
+++ b/crdesigner/ui/gui/utilities/sumo_settings.py
@@ -1,6 +1,14 @@
 from commonroad.common.util import Interval
 from commonroad.scenario.obstacle import ObstacleType
-from PyQt6.QtWidgets import QMessageBox
+
+try:
+    # required for Ubuntu 20.04 since there a system library is too old for pyqt6 and the import fails
+    # when not importing this, one can still use the map conversion
+    from PyQt6.QtWidgets import QMessageBox
+
+    pyqt_available = True
+except (ImportError, RuntimeError):
+    pyqt_available = False
 
 from crdesigner.map_conversion.sumo_map.config import SumoConfig
 from crdesigner.ui.gui.utilities.util import Observable
@@ -162,5 +170,6 @@ def restore_defaults(self):
         self.update_ui_values()
 
     def warn(self, msg):
-        messbox = QMessageBox()
-        messbox.warning(None, "Warning", msg, QMessageBox.Ok, QMessageBox.Ok)
+        if pyqt_available:
+            messbox = QMessageBox()
+            messbox.warning(None, "Warning", msg, QMessageBox.StandardButton.Ok, QMessageBox.StandardButton.Ok)
diff --git a/crdesigner/ui/gui/view/mwindow_ui.py b/crdesigner/ui/gui/view/mwindow_ui.py
index deb8487d..f80fbb10 100644
--- a/crdesigner/ui/gui/view/mwindow_ui.py
+++ b/crdesigner/ui/gui/view/mwindow_ui.py
@@ -6,8 +6,8 @@
 from PyQt6.QtWidgets import QApplication, QMainWindow, QMessageBox
 
 from crdesigner.common.config.gui_config import ColorSchema, gui_config
+from crdesigner.common.sumo_available import SUMO_AVAILABLE
 from crdesigner.ui.gui.resources.MainWindow import Ui_mainWindow
-from crdesigner.ui.gui.utilities.gui_sumo_simulation import SUMO_AVAILABLE
 
 if SUMO_AVAILABLE:
     pass
diff --git a/tutorials/conversion_examples/example_commonroad_to_sumo.py b/tutorials/conversion_examples/example_commonroad_to_sumo.py
index cff0e11e..62e719d4 100644
--- a/tutorials/conversion_examples/example_commonroad_to_sumo.py
+++ b/tutorials/conversion_examples/example_commonroad_to_sumo.py
@@ -7,8 +7,8 @@
 
 from crdesigner.common.file_reader import CRDesignerFileReader
 from crdesigner.common.file_writer import CRDesignerFileWriter, OverwriteExistingFile
+from crdesigner.common.sumo_available import SUMO_AVAILABLE
 from crdesigner.map_conversion.map_conversion_interface import commonroad_to_sumo
-from crdesigner.ui.gui.utilities.gui_sumo_simulation import SUMO_AVAILABLE
 
 if SUMO_AVAILABLE:
     from sumocr.interface.sumo_simulation import SumoSimulation
diff --git a/tutorials/conversion_examples/example_sumo_to_commonroad.py b/tutorials/conversion_examples/example_sumo_to_commonroad.py
index 2d46da8b..4ee13c8b 100644
--- a/tutorials/conversion_examples/example_sumo_to_commonroad.py
+++ b/tutorials/conversion_examples/example_sumo_to_commonroad.py
@@ -4,8 +4,8 @@
 from commonroad.scenario.scenario import Tag
 
 from crdesigner.common.file_writer import CRDesignerFileWriter, OverwriteExistingFile
+from crdesigner.common.sumo_available import SUMO_AVAILABLE
 from crdesigner.map_conversion.map_conversion_interface import sumo_to_commonroad
-from crdesigner.ui.gui.utilities.gui_sumo_simulation import SUMO_AVAILABLE
 
 if SUMO_AVAILABLE:
     from crdesigner.map_conversion.sumo_map.sumo2cr import convert_net_to_cr