diff --git a/cura/CuraPackageManager.py b/cura/CuraPackageManager.py
index 363b8034ec..6422469bdf 100644
--- a/cura/CuraPackageManager.py
+++ b/cura/CuraPackageManager.py
@@ -1,6 +1,8 @@
 # Copyright (c) 2018 Ultimaker B.V.
 # Cura is released under the terms of the LGPLv3 or higher.
 
+from typing import List, Tuple
+
 from cura.CuraApplication import CuraApplication #To find some resource types.
 from cura.Settings.GlobalStack import GlobalStack
 
@@ -22,7 +24,7 @@ class CuraPackageManager(PackageManager):
     #   empty if it is never used.
     #   It loops through all the package contents and see if some of the ids are used.
     #   The list consists of 3-tuples: (global_stack, extruder_nr, container_id)
-    def getMachinesUsingPackage(self, package_id: str):
+    def getMachinesUsingPackage(self, package_id: str) -> Tuple[List[Tuple[GlobalStack, str, str]], List[Tuple[GlobalStack, str, str]]]:
         ids = self.getPackageContainerIds(package_id)
         container_stacks = self._application.getContainerRegistry().findContainerStacks()
         global_stacks = [container_stack for container_stack in container_stacks if isinstance(container_stack, GlobalStack)]
diff --git a/cura/Machines/MaterialGroup.py b/cura/Machines/MaterialGroup.py
index e05647e674..8a73796a7a 100644
--- a/cura/Machines/MaterialGroup.py
+++ b/cura/Machines/MaterialGroup.py
@@ -24,8 +24,8 @@ class MaterialGroup:
     def __init__(self, name: str, root_material_node: "MaterialNode") -> None:
         self.name = name
         self.is_read_only = False
-        self.root_material_node = root_material_node  # type: MaterialNode
-        self.derived_material_node_list = []  # type: List[MaterialNode]
+        self.root_material_node = root_material_node # type: MaterialNode
+        self.derived_material_node_list = [] # type: List[MaterialNode]
 
     def __str__(self) -> str:
         return "%s[%s]" % (self.__class__.__name__, self.name)
diff --git a/plugins/Toolbox/resources/qml/ToolboxConfirmUninstallResetDialog.qml b/plugins/Toolbox/resources/qml/ToolboxConfirmUninstallResetDialog.qml
index 83ace5f80b..4aa8b883b7 100644
--- a/plugins/Toolbox/resources/qml/ToolboxConfirmUninstallResetDialog.qml
+++ b/plugins/Toolbox/resources/qml/ToolboxConfirmUninstallResetDialog.qml
@@ -32,11 +32,14 @@ UM.Dialog
     {
         UM.I18nCatalog { id: catalog; name: "cura" }
 
-        anchors.fill: parent
-        anchors.leftMargin: Math.round(20 * screenScaleFactor)
-        anchors.rightMargin: Math.round(20 * screenScaleFactor)
-        anchors.topMargin: Math.round(10 * screenScaleFactor)
-        anchors.bottomMargin: Math.round(10 * screenScaleFactor)
+        anchors
+        {
+            fill: parent
+            leftMargin: Math.round(20 * screenScaleFactor)
+            rightMargin: Math.round(20 * screenScaleFactor)
+            topMargin: Math.round(10 * screenScaleFactor)
+            bottomMargin: Math.round(10 * screenScaleFactor)
+        }
         spacing: Math.round(15 * screenScaleFactor)
 
         Label
diff --git a/plugins/Toolbox/src/Toolbox.py b/plugins/Toolbox/src/Toolbox.py
index 31b9dda9f4..b1128722e9 100644
--- a/plugins/Toolbox/src/Toolbox.py
+++ b/plugins/Toolbox/src/Toolbox.py
@@ -330,7 +330,10 @@ class Toolbox(QObject, Extension):
             if self._confirm_reset_dialog is None:
                 self._confirm_reset_dialog = self._createDialog("ToolboxConfirmUninstallResetDialog.qml")
             self.uninstallVariablesChanged.emit()
-            self._confirm_reset_dialog.show()
+            if self._confirm_reset_dialog is None:
+                Logger.log("e", "ToolboxConfirmUninstallResetDialog should have been initialized, but it is not. Not showing dialog and not uninstalling package.")
+            else:
+                self._confirm_reset_dialog.show()
         else:
             # Plain uninstall
             self.uninstall(package_id)
@@ -368,13 +371,13 @@ class Toolbox(QObject, Extension):
             default_quality_group = quality_manager.getDefaultQualityType(global_stack)
             machine_manager.setQualityGroup(default_quality_group, global_stack = global_stack)
 
-        self._markPackageMaterialsAsRemove(self._package_id_to_uninstall)
+        self._markPackageMaterialsAsToBeUninstalled(self._package_id_to_uninstall)
 
         self.uninstall(self._package_id_to_uninstall)
         self._resetUninstallVariables()
         self.closeConfirmResetDialog()
 
-    def _markPackageMaterialsAsRemove(self, package_id: str) -> None:
+    def _markPackageMaterialsAsToBeUninstalled(self, package_id: str) -> None:
         container_registry = self._application.getContainerRegistry()
 
         all_containers = self._package_manager.getPackageContainerIds(package_id)
diff --git a/plugins/UM3NetworkPrinting/LegacyUM3OutputDevice.py b/plugins/UM3NetworkPrinting/LegacyUM3OutputDevice.py
index 4c5d56e0da..f38c1a1c7a 100644
--- a/plugins/UM3NetworkPrinting/LegacyUM3OutputDevice.py
+++ b/plugins/UM3NetworkPrinting/LegacyUM3OutputDevice.py
@@ -455,8 +455,14 @@ class LegacyUM3OutputDevice(NetworkedPrinterOutputDevice):
             self.setAuthenticationState(AuthState.AuthenticationDenied)
             self._authentication_failed_message.show()
 
-    def _saveAuthentication(self):
+    def _saveAuthentication(self) -> None:
         global_container_stack = CuraApplication.getInstance().getGlobalContainerStack()
+        if self._authentication_key is None:
+            Logger.log("e", "Authentication key is None, nothing to save.")
+            return
+        if self._authentication_id is None:
+            Logger.log("e", "Authentication id is None, nothing to save.")
+            return
         if global_container_stack:
             global_container_stack.setMetaDataEntry("network_authentication_key", self._authentication_key)
 
@@ -631,4 +637,4 @@ class LegacyUM3OutputDevice(NetworkedPrinterOutputDevice):
             result = "********" + result
             return result
 
-        return self._authentication_key
\ No newline at end of file
+        return self._authentication_key