diff --git a/cura/Settings/ExtruderManager.py b/cura/Settings/ExtruderManager.py
index c2fe929957..51e7e81fef 100755
--- a/cura/Settings/ExtruderManager.py
+++ b/cura/Settings/ExtruderManager.py
@@ -402,7 +402,8 @@ class ExtruderManager(QObject):
 
             # Register the extruder trains by position
             for extruder_train in extruder_trains:
-                self._extruder_trains[global_stack_id][extruder_train.getMetaDataEntry("position")] = extruder_train
+                extruder_position = extruder_train.getMetaDataEntry("position")
+                self._extruder_trains[global_stack_id][extruder_position] = extruder_train
 
                 # regardless of what the next stack is, we have to set it again, because of signal routing. ???
                 extruder_train.setParent(global_stack)
diff --git a/cura/Settings/GlobalStack.py b/cura/Settings/GlobalStack.py
index 5d8a4505a5..cea59bcb70 100755
--- a/cura/Settings/GlobalStack.py
+++ b/cura/Settings/GlobalStack.py
@@ -153,6 +153,23 @@ class GlobalStack(CuraContainerStack):
 
         return True
 
+    ##  Perform some sanity checks on the global stack
+    #   Sanity check for extruders; they must have positions 0 and up to machine_extruder_count - 1
+    def isValid(self):
+        container_registry = ContainerRegistry.getInstance()
+        extruder_trains = container_registry.findContainerStacks(type = "extruder_train", machine = self.getId())
+
+        machine_extruder_count = self.getProperty("machine_extruder_count", "value")
+        extruder_check_position = set()
+        for extruder_train in extruder_trains:
+            extruder_position = extruder_train.getMetaDataEntry("position")
+            extruder_check_position.add(extruder_position)
+
+        for check_position in range(machine_extruder_count):
+            if str(check_position) not in extruder_check_position:
+                return False
+        return True
+
 
 ## private:
 global_stack_mime = MimeType(
diff --git a/cura/Settings/MachineManager.py b/cura/Settings/MachineManager.py
index 14f4f5fc33..c2b1e6dc5f 100755
--- a/cura/Settings/MachineManager.py
+++ b/cura/Settings/MachineManager.py
@@ -6,6 +6,7 @@ import time
 #Type hinting.
 from typing import List, Dict, TYPE_CHECKING, Optional
 
+from UM.ConfigurationErrorMessage import ConfigurationErrorMessage
 from UM.Scene.Iterator.DepthFirstIterator import DepthFirstIterator
 from UM.Signal import Signal
 
@@ -165,8 +166,6 @@ class MachineManager(QObject):
         if active_machine_id != "" and ContainerRegistry.getInstance().findContainerStacksMetadata(id = active_machine_id):
             # An active machine was saved, so restore it.
             self.setActiveMachine(active_machine_id)
-            # Make sure _active_container_stack is properly initiated
-            ExtruderManager.getInstance().setActiveExtruderIndex(0)
 
     def _onOutputDevicesChanged(self) -> None:
         self._printer_output_devices = []
@@ -357,6 +356,10 @@ class MachineManager(QObject):
             return
 
         global_stack = containers[0]
+        if not global_stack.isValid():
+            # Mark global stack as invalid
+            ConfigurationErrorMessage.getInstance().addFaultyContainers(global_stack.getId())
+            return  # We're done here
         ExtruderManager.getInstance().setActiveExtruderIndex(0)  # Switch to first extruder
         self._global_container_stack = global_stack
         Application.getInstance().setGlobalContainerStack(global_stack)
diff --git a/plugins/MachineSettingsAction/MachineSettingsAction.py b/plugins/MachineSettingsAction/MachineSettingsAction.py
index ded59bf934..7d5b317475 100755
--- a/plugins/MachineSettingsAction/MachineSettingsAction.py
+++ b/plugins/MachineSettingsAction/MachineSettingsAction.py
@@ -56,8 +56,6 @@ class MachineSettingsAction(MachineAction):
             if self._isEmptyDefinitionChanges(definition_changes_id):
                 return
 
-            self._container_registry.removeContainer(definition_changes_id)
-
     def _reset(self):
         if not self._global_container_stack:
             return