diff --git a/resources/qml/SidebarHeader.qml b/resources/qml/SidebarHeader.qml
index 74e189789d..dcb351e866 100644
--- a/resources/qml/SidebarHeader.qml
+++ b/resources/qml/SidebarHeader.qml
@@ -347,7 +347,8 @@ Column
             id: materialSelection
 
             property var activeExtruder: Cura.MachineManager.activeStack
-            property var currentRootMaterialName: activeExtruder.material.name
+            property var hasActiveExtruder: activeExtruder != null
+            property var currentRootMaterialName: hasActiveExtruder ? activeExtruder.material.name : ""
 
             text: currentRootMaterialName
             tooltip: currentRootMaterialName
@@ -366,6 +367,10 @@ Column
             property var valueWarning: ! Cura.MachineManager.isActiveQualitySupported
 
             function isMaterialSupported () {
+                if (!hasActiveExtruder)
+                {
+                    return false;
+                }
                 return Cura.ContainerManager.getContainerMetaDataEntry(activeExtruder.material.id, "compatible") == "True"
             }
         }
diff --git a/resources/qml/WorkspaceSummaryDialog.qml b/resources/qml/WorkspaceSummaryDialog.qml
index 12eba13dd9..cf19e45fdd 100644
--- a/resources/qml/WorkspaceSummaryDialog.qml
+++ b/resources/qml/WorkspaceSummaryDialog.qml
@@ -101,7 +101,7 @@ UM.Dialog
                 }
                 Label
                 {
-                    text: Cura.MachineManager.activeMachine.definition.name
+                    text: (Cura.MachineManager.activeMachine == null) ? "" : Cura.MachineManager.activeMachine.definition.name
                     width: (parent.width / 3) | 0
                 }
             }