diff --git a/plugins/UM3NetworkPrinting/NetworkPrinterOutputDevice.py b/plugins/UM3NetworkPrinting/NetworkPrinterOutputDevice.py
index a3df717a67..64386fb482 100755
--- a/plugins/UM3NetworkPrinting/NetworkPrinterOutputDevice.py
+++ b/plugins/UM3NetworkPrinting/NetworkPrinterOutputDevice.py
@@ -485,6 +485,7 @@ class NetworkPrinterOutputDevice(PrinterOutputDevice):
                         Logger.log("d", "Stopping post upload because the connection was lost.")
                         try:
                             self._post_reply.uploadProgress.disconnect(self._onUploadProgress)
+                            self._post_reply.finished.disconnect(self._onUploadFinished)
                         except TypeError:
                             pass  # The disconnection can fail on mac in some cases. Ignore that.
 
@@ -517,6 +518,7 @@ class NetworkPrinterOutputDevice(PrinterOutputDevice):
                         Logger.log("d", "Stopping post upload because the connection was lost.")
                         try:
                             self._post_reply.uploadProgress.disconnect(self._onUploadProgress)
+                            self._post_reply.finished.disconnect(self._onUploadFinished)
                         except TypeError:
                             pass  # The disconnection can fail on mac in some cases. Ignore that.
 
@@ -652,14 +654,6 @@ class NetworkPrinterOutputDevice(PrinterOutputDevice):
     #   \param kwargs Keyword arguments.
     def requestWrite(self, nodes, file_name=None, filter_by_machine=False, file_handler=None, **kwargs):
 
-        # Check if we're already writing
-        if not self._write_finished:
-            self._error_message = Message(
-                i18n_catalog.i18nc("@info:status",
-                                   "Sending new jobs (temporarily) blocked, still sending the previous print job."))
-            self._error_message.show()
-            return
-
         if self._printer_state not in ["idle", ""]:
             self._error_message = Message(
                 i18n_catalog.i18nc("@info:status", "Unable to start a new print job, printer is busy. Current printer status is %s.") % self._printer_state,
@@ -759,6 +753,14 @@ class NetworkPrinterOutputDevice(PrinterOutputDevice):
                                                  )
             return
 
+        # Check if we're already writing
+        if not self._write_finished:
+            self._error_message = Message(
+                i18n_catalog.i18nc("@info:status",
+                                   "Sending new jobs (temporarily) blocked, still sending the previous print job."))
+            self._error_message.show()
+            return
+
         # Indicate we're starting a new write action, is set back to True in the startPrint() method
         self._write_finished = False
 
@@ -996,6 +998,7 @@ class NetworkPrinterOutputDevice(PrinterOutputDevice):
             if self._post_reply:
                 self._post_reply.abort()
                 self._post_reply.uploadProgress.disconnect(self._onUploadProgress)
+                self._post_reply.finished.disconnect(self._onUploadFinished)
                 Logger.log("d", "Uploading of print failed after %s", time() - self._send_gcode_start)
                 self._post_reply = None
                 self._progress_message.hide()
@@ -1177,6 +1180,7 @@ class NetworkPrinterOutputDevice(PrinterOutputDevice):
                 del self._material_post_objects[id(reply)]
             elif "print_job" in reply_url:
                 reply.uploadProgress.disconnect(self._onUploadProgress)
+                reply.finished.disconnect(self._onUploadFinished)
                 Logger.log("d", "Uploading of print succeeded after %s", time() - self._send_gcode_start)
                 # Only reset the _post_reply if it was the same one.
                 if reply == self._post_reply: