diff --git a/plugins/UM3NetworkPrinting/src/Messages/PrintJobUploadBlockedMessage.py b/plugins/UM3NetworkPrinting/src/Messages/PrintJobUploadBlockedMessage.py
index b8bef06b44..be00292559 100644
--- a/plugins/UM3NetworkPrinting/src/Messages/PrintJobUploadBlockedMessage.py
+++ b/plugins/UM3NetworkPrinting/src/Messages/PrintJobUploadBlockedMessage.py
@@ -3,9 +3,11 @@
 from UM import i18nCatalog
 from UM.Message import Message
 
+
 I18N_CATALOG = i18nCatalog("cura")
 
 
+## Message shown when uploading a print job to a cluster is blocked because another upload is already in progress.
 class PrintJobUploadBlockedMessage(Message):
     
     def __init__(self) -> None:
diff --git a/plugins/UM3NetworkPrinting/src/Messages/PrintJobUploadErrorMessage.py b/plugins/UM3NetworkPrinting/src/Messages/PrintJobUploadErrorMessage.py
index 1f0d87b76d..bb26a84953 100644
--- a/plugins/UM3NetworkPrinting/src/Messages/PrintJobUploadErrorMessage.py
+++ b/plugins/UM3NetworkPrinting/src/Messages/PrintJobUploadErrorMessage.py
@@ -3,12 +3,14 @@
 from UM import i18nCatalog
 from UM.Message import Message
 
+
 I18N_CATALOG = i18nCatalog("cura")
 
 
+## Message shown when uploading a print job to a cluster failed.
 class PrintJobUploadErrorMessage(Message):
     
-    def __init__(self, message: str) -> None:
+    def __init__(self, message: str = None) -> None:
         super().__init__(
             text = message or I18N_CATALOG.i18nc("@info:text", "Could not upload the data to the printer."),
             title = I18N_CATALOG.i18nc("@info:title", "Network error"),
diff --git a/plugins/UM3NetworkPrinting/src/Messages/PrintJobUploadSuccessMessage.py b/plugins/UM3NetworkPrinting/src/Messages/PrintJobUploadSuccessMessage.py
index f7076351c8..c9be28d57f 100644
--- a/plugins/UM3NetworkPrinting/src/Messages/PrintJobUploadSuccessMessage.py
+++ b/plugins/UM3NetworkPrinting/src/Messages/PrintJobUploadSuccessMessage.py
@@ -7,6 +7,7 @@ from UM.Message import Message
 I18N_CATALOG = i18nCatalog("cura")
 
 
+## Message shown when uploading a print job to a cluster succeeded.
 class PrintJobUploadSuccessMessage(Message):
     
     def __init__(self) -> None: