diff -r d73af2eeea05 -r 2c0511479b18 BeremizIDE.py
--- a/BeremizIDE.py	Fri Sep 10 14:42:46 2021 +0200
+++ b/BeremizIDE.py	Fri Sep 10 14:44:20 2021 +0200
@@ -625,6 +625,7 @@
         if self.CTR is None or self.CheckSaveBeforeClosing(_("Close Application")):
             if self.CTR is not None:
                 self.CTR.KillDebugThread()
+                self.CTR._Disconnect()
             self.KillLocalRuntime()
 
             self.SaveLastState()