diff --git a/cura/Machines/Models/BaseMaterialsModel.py b/cura/Machines/Models/BaseMaterialsModel.py
index aa8552bebb..776d540867 100644
--- a/cura/Machines/Models/BaseMaterialsModel.py
+++ b/cura/Machines/Models/BaseMaterialsModel.py
@@ -154,7 +154,7 @@ class BaseMaterialsModel(ListModel):
 
         # Update the available materials (ContainerNode) for the current active machine and extruder setup.
         global_stack = cura.CuraApplication.CuraApplication.getInstance().getGlobalContainerStack()
-        if not global_stack.hasMaterials:
+        if not global_stack or not global_stack.hasMaterials:
             return  # There are no materials for this machine, so nothing to do.
         extruder_list = global_stack.extruderList
         if self._extruder_position > len(extruder_list):
diff --git a/cura/Settings/MachineManager.py b/cura/Settings/MachineManager.py
index e5eec988e7..516579ede2 100755
--- a/cura/Settings/MachineManager.py
+++ b/cura/Settings/MachineManager.py
@@ -290,9 +290,15 @@ class MachineManager(QObject):
             self.activeStackValueChanged.emit()
 
     @pyqtSlot(str)
-    def setActiveMachine(self, stack_id: str) -> None:
+    def setActiveMachine(self, stack_id: Optional[str]) -> None:
         self.blurSettings.emit()  # Ensure no-one has focus.
 
+        if not stack_id:
+            self._application.setGlobalContainerStack(None)
+            self.globalContainerChanged.emit()
+            self._application.showAddPrintersUncancellableDialog.emit()
+            return
+
         container_registry = CuraContainerRegistry.getInstance()
         containers = container_registry.findContainerStacks(id = stack_id)
         if not containers:
@@ -717,6 +723,8 @@ class MachineManager(QObject):
             other_machine_stacks = [s for s in machine_stacks if s["id"] != machine_id]
             if other_machine_stacks:
                 self.setActiveMachine(other_machine_stacks[0]["id"])
+            else:
+                self.setActiveMachine(None)
 
         metadatas = CuraContainerRegistry.getInstance().findContainerStacksMetadata(id = machine_id)
         if not metadatas:
diff --git a/resources/qml/Dialogs/WorkspaceSummaryDialog.qml b/resources/qml/Dialogs/WorkspaceSummaryDialog.qml
index 6fe9607274..670766204f 100644
--- a/resources/qml/Dialogs/WorkspaceSummaryDialog.qml
+++ b/resources/qml/Dialogs/WorkspaceSummaryDialog.qml
@@ -143,7 +143,7 @@ UM.Dialog
                 {
                     width: parent.width
                     height: childrenRect.height
-                    model: Cura.MachineManager.activeMachine.extruderList
+                    model: Cura.MachineManager.activeMachine ? Cura.MachineManager.activeMachine.extruderList : null
                     delegate: Column
                     {
                         height: childrenRect.height
diff --git a/resources/qml/Menus/ConfigurationMenu/ConfigurationMenu.qml b/resources/qml/Menus/ConfigurationMenu/ConfigurationMenu.qml
index 9891fc1d69..0d7a5886d2 100644
--- a/resources/qml/Menus/ConfigurationMenu/ConfigurationMenu.qml
+++ b/resources/qml/Menus/ConfigurationMenu/ConfigurationMenu.qml
@@ -33,7 +33,7 @@ Cura.ExpandablePopup
     }
 
     contentPadding: UM.Theme.getSize("default_lining").width
-    enabled: Cura.MachineManager.activeMachine.hasMaterials || Cura.MachineManager.activeMachine.hasVariants || Cura.MachineManager.activeMachine.hasVariantBuildplates; //Only let it drop down if there is any configuration that you could change.
+    enabled: Cura.MachineManager.activeMachine ? Cura.MachineManager.activeMachine.hasMaterials || Cura.MachineManager.activeMachine.hasVariants || Cura.MachineManager.activeMachine.hasVariantBuildplates : false; //Only let it drop down if there is any configuration that you could change.
 
     headerItem: Item
     {
@@ -84,7 +84,7 @@ Cura.ExpandablePopup
                     {
                         id: variantLabel
 
-                        visible: Cura.MachineManager.activeMachine.hasVariants
+                        visible: Cura.MachineManager.activeMachine ? Cura.MachineManager.activeMachine.hasVariants : false
 
                         text: model.variant
                         elide: Text.ElideRight
@@ -114,7 +114,7 @@ Cura.ExpandablePopup
             color: UM.Theme.getColor("text")
             renderType: Text.NativeRendering
 
-            visible: !Cura.MachineManager.activeMachine.hasMaterials && (Cura.MachineManager.activeMachine.hasVariants || Cura.MachineManager.activeMachine.hasVariantBuildplates)
+            visible: Cura.MachineManager.activeMachine ? !Cura.MachineManager.activeMachine.hasMaterials && (Cura.MachineManager.activeMachine.hasVariants || Cura.MachineManager.activeMachine.hasVariantBuildplates) : false
 
             anchors
             {
diff --git a/resources/qml/Menus/ConfigurationMenu/CustomConfiguration.qml b/resources/qml/Menus/ConfigurationMenu/CustomConfiguration.qml
index 65f5bcce8c..010e2e77b0 100644
--- a/resources/qml/Menus/ConfigurationMenu/CustomConfiguration.qml
+++ b/resources/qml/Menus/ConfigurationMenu/CustomConfiguration.qml
@@ -244,7 +244,7 @@ Item
             Row
             {
                 height: visible ? UM.Theme.getSize("print_setup_big_item").height : 0
-                visible: Cura.MachineManager.activeMachine.hasMaterials
+                visible: Cura.MachineManager.activeMachine ? Cura.MachineManager.activeMachine.hasMaterials : false
 
                 Label
                 {
@@ -305,7 +305,7 @@ Item
             Row
             {
                 height: visible ? UM.Theme.getSize("print_setup_big_item").height : 0
-                visible: Cura.MachineManager.activeMachine.hasVariants
+                visible: Cura.MachineManager.activeMachine ? Cura.MachineManager.activeMachine.hasVariants : false
 
                 Label
                 {
diff --git a/resources/qml/PrintSetupSelector/Recommended/RecommendedSupportSelector.qml b/resources/qml/PrintSetupSelector/Recommended/RecommendedSupportSelector.qml
index f227dddaf9..92f0024b23 100644
--- a/resources/qml/PrintSetupSelector/Recommended/RecommendedSupportSelector.qml
+++ b/resources/qml/PrintSetupSelector/Recommended/RecommendedSupportSelector.qml
@@ -130,7 +130,11 @@ Item
                 target: extruderModel
                 onModelChanged:
                 {
-                    supportExtruderCombobox.color = supportExtruderCombobox.model.getItem(supportExtruderCombobox.currentIndex).color
+                    var maybeColor = supportExtruderCombobox.model.getItem(supportExtruderCombobox.currentIndex).color
+                    if (maybeColor)
+                    {
+                        supportExtruderCombobox.color = maybeColor
+                    }
                 }
             }
             onCurrentIndexChanged:
diff --git a/resources/qml/PrinterSelector/MachineSelectorList.qml b/resources/qml/PrinterSelector/MachineSelectorList.qml
index a7c041630f..18b1a68b20 100644
--- a/resources/qml/PrinterSelector/MachineSelectorList.qml
+++ b/resources/qml/PrinterSelector/MachineSelectorList.qml
@@ -28,11 +28,11 @@ ListView
 
     delegate: MachineSelectorButton
     {
-        text: model.name
+        text: model.name ? model.name : ""
         width: listView.width
         outputDevice: Cura.MachineManager.printerOutputDevices.length >= 1 ? Cura.MachineManager.printerOutputDevices[0] : null
 
-        checked: Cura.MachineManager.activeMachine.id == model.id
+        checked: Cura.MachineManager.activeMachine ? Cura.MachineManager.activeMachine.id == model.id : false
 
         onClicked:
         {