diff --git a/template/engine/sequencer.py b/template/engine/sequencer.py
index 040ee0e..2541da2 100644
--- a/template/engine/sequencer.py
+++ b/template/engine/sequencer.py
@@ -369,7 +369,14 @@ class SequencerInterface(_Interface): #Basically the midi part of a track.
         undo. That is why we bother setting calfboxTrack to None
         again.
         """
-        portlist = cbox.JackIO.get_connected_ports(self.cboxPortName())
+        if not self.calfboxTrack: #maybe non-template part deactivated it, like Patroneo groups
+            return
+
+        try:
+            portlist = cbox.JackIO.get_connected_ports(self.cboxPortName())
+        except: #port not found.
+            portlist = []
+
         self._beforeDeleteThisJackMidiWasConnectedTo = portlist
 
         self.calfboxTrack.set_external_output("")