diff --git a/cura/Settings/MachineManager.py b/cura/Settings/MachineManager.py
index f1bb8b6648..253c5f793c 100755
--- a/cura/Settings/MachineManager.py
+++ b/cura/Settings/MachineManager.py
@@ -498,6 +498,11 @@ class MachineManager(QObject):
     @pyqtProperty("QVariantList", notify=activeVariantChanged)
     def activeVariantNames(self) -> List[str]:
         result = []
+
+        # it can happen when there is no active machine
+        if self._global_container_stack is None:
+            return result
+
         active_stacks = ExtruderManager.getInstance().getActiveGlobalAndExtruderStacks()
         if active_stacks is not None:
             for stack in active_stacks:
@@ -510,6 +515,11 @@ class MachineManager(QObject):
     @pyqtProperty("QVariantList", notify = activeMaterialChanged)
     def activeMaterialNames(self) -> List[str]:
         result = []
+
+        # it can happen when there is no active machine
+        if self._global_container_stack is None:
+            return result
+
         active_stacks = ExtruderManager.getInstance().getActiveGlobalAndExtruderStacks()
         if active_stacks is not None:
             for stack in active_stacks:
@@ -530,6 +540,11 @@ class MachineManager(QObject):
     @pyqtProperty("QVariantMap", notify = activeVariantChanged)
     def allActiveVariantIds(self) -> Dict[str, str]:
         result = {}
+
+        # it can happen when there is no active machine
+        if self._global_container_stack is None:
+            return result
+
         active_stacks = ExtruderManager.getInstance().getActiveExtruderStacks()
         if active_stacks is not None: #If we have a global stack.
             for stack in active_stacks:
@@ -548,6 +563,11 @@ class MachineManager(QObject):
     @pyqtProperty("QVariantMap", notify = activeMaterialChanged)
     def allActiveMaterialIds(self) -> Dict[str, str]:
         result = {}
+
+        # it can happen when there is no active machine
+        if self._global_container_stack is None:
+            return result
+
         active_stacks = ExtruderManager.getInstance().getActiveExtruderStacks()
 
         result[self._global_container_stack.getId()] = self._global_container_stack.material.getId()