diff --git a/plugins/Toolbox/src/CloudApiModel.py b/plugins/Toolbox/src/CloudApiModel.py
index 082a28a24c..31c3139262 100644
--- a/plugins/Toolbox/src/CloudApiModel.py
+++ b/plugins/Toolbox/src/CloudApiModel.py
@@ -1,3 +1,5 @@
+from typing import Union
+
 from cura import ApplicationMetadata, UltimakerCloudAuthentication
 
 
diff --git a/plugins/Toolbox/src/CloudSync/DownloadPresenter.py b/plugins/Toolbox/src/CloudSync/DownloadPresenter.py
index 492ccdf186..dcb74ca41f 100644
--- a/plugins/Toolbox/src/CloudSync/DownloadPresenter.py
+++ b/plugins/Toolbox/src/CloudSync/DownloadPresenter.py
@@ -29,7 +29,7 @@ class DownloadPresenter:
         self._scope = UltimakerCloudScope(app)
 
         self._started = False
-        self._progress_message = None  # type: Optional[Message]
+        self._progress_message = self._createProgressMessage()
         self._progress = {}  # type: Dict[str, Dict[str, Any]] # package_id, Dict
         self._error = []  # type: List[str] # package_id
 
@@ -57,7 +57,7 @@ class DownloadPresenter:
             }
 
         self._started = True
-        self._showProgressMessage()
+        self._progress_message.show()
 
     def abort(self):
         manager = HttpRequestManager.getInstance()
@@ -70,15 +70,14 @@ class DownloadPresenter:
         self.done.disconnectAll()
         return DownloadPresenter(self._app)
 
-    def _showProgressMessage(self):
-        self._progress_message = Message(i18n_catalog.i18nc(
+    def _createProgressMessage(self) -> Message:
+        return Message(i18n_catalog.i18nc(
             "@info:generic",
             "\nSyncing..."),
             lifetime = 0,
             use_inactivity_timer=False,
             progress = 0.0,
             title = i18n_catalog.i18nc("@info:title", "Changes detected from your Ultimaker account", ))
-        self._progress_message.show()
 
     def _onFinished(self, package_id: str, reply: QNetworkReply):
         self._progress[package_id]["received"] = self._progress[package_id]["total"]
@@ -110,7 +109,7 @@ class DownloadPresenter:
 
         self._progress_message.setProgress(100.0 * (received / total))  # [0 .. 100] %
 
-    def _onError(self, package_id: str):
+    def _onError(self, package_id: str) -> None:
         self._progress.pop(package_id)
         self._error.append(package_id)
         self._checkDone()
@@ -125,3 +124,4 @@ class DownloadPresenter:
 
         self._progress_message.hide()
         self.done.emit(success_items, error_items)
+        return True
diff --git a/plugins/Toolbox/src/CloudSync/LicensePresenter.py b/plugins/Toolbox/src/CloudSync/LicensePresenter.py
index 9e77002aa1..f05feecabd 100644
--- a/plugins/Toolbox/src/CloudSync/LicensePresenter.py
+++ b/plugins/Toolbox/src/CloudSync/LicensePresenter.py
@@ -1,5 +1,5 @@
 import os
-from typing import Dict, Optional
+from typing import Dict, Optional, List
 
 from PyQt5.QtCore import QObject, pyqtSlot
 
@@ -24,7 +24,7 @@ class LicensePresenter(QObject):
         self.licenseAnswers = Signal()
 
         self._current_package_idx = 0
-        self._package_models = None  # type: Optional[Dict]
+        self._package_models = []  # type: List[Dict]
         self._license_model = LicenseModel()  # type: LicenseModel
 
         self._app = app
diff --git a/plugins/Toolbox/src/CloudSync/SyncOrchestrator.py b/plugins/Toolbox/src/CloudSync/SyncOrchestrator.py
index af9f1440e6..a207523067 100644
--- a/plugins/Toolbox/src/CloudSync/SyncOrchestrator.py
+++ b/plugins/Toolbox/src/CloudSync/SyncOrchestrator.py
@@ -70,7 +70,7 @@ class SyncOrchestrator(Extension):
         self._license_presenter.present(plugin_path, success_items)
 
     # Called when user has accepted / declined all licenses for the downloaded packages
-    def _onLicenseAnswers(self, answers: [Dict[str, Any]]):
+    def _onLicenseAnswers(self, answers: List[Dict[str, Any]]):
         Logger.debug("Got license answers: {}", answers)
 
         has_changes = False  # True when at least one package is installed