Fix crash when trying to edit a hidden track in the track editor

engine/items.py

@@ -2403,7 +2403,7 @@ class Clef(Item):
             }
 
     def _lilypond(self, carryLilypondRanges):
-        return "\\clef \"{}\"".format(self.clefString)
+        return f'\\clef "{self.clefString}"'
 
 class TimeSignature(Item): #Deprecated since 1750
     """Meter information. Nominator is how many notes in one measure and

engine/track.py

@@ -857,7 +857,7 @@ class Track(object):
                 clef = ""
                 break
         else:
-            clef = "\\clef " + self.initialClefKeyword + "\n" #internal clef keywords are the same as lilypond
+            clef = "\\clef \"" + self.initialClefKeyword + "\"\n" #internal clef keywords are the same as lilypond
 
         #Initial Key Signature
         for item in self.blocks[0].data[:4]:

qtgui/trackEditor.py

@@ -393,7 +393,10 @@ class TrackEditor(QtWidgets.QWidget):
                 widget = TrackWidget(self, trackExportObject)
                 self.tracks[trackExportObject["id"]] = widget
                 self.layout.insertWidget(-1, widget)
-                widget.setTitle(f'Track {trackExportObject["index"]+1} - id: {trackExportObject["id"]}')
+                if trackExportObject["index"]: #track visible?
+                    widget.setTitle(f'Track {trackExportObject["index"]+1} - id: {trackExportObject["id"]}')
+                else:
+                    widget.setTitle(f'Track id: {trackExportObject["id"]}')
             else:
                 leftOver.remove(trackExportObject["id"])