actually fix

gui.py

@@ -509,12 +509,12 @@ class DocumentWindow(QMainWindow):
 
             self.window.chordTableView.populate(self.doc.chordList)
             # remove the chord if any of the blocks have it attached
-            for s in self.doc.sectionList:
-                    for b in s.blockList:
-                        if b.chord:
-                            if b.chord.name == oldName:
-                                b.chord = None
-            if self.currentSection.blockList is not None:
+            if self.currentSection is not None:
+                for s in self.doc.sectionList:
+                        for b in s.blockList:
+                            if b.chord:
+                                if b.chord.name == oldName:
+                                    b.chord = None
                 self.window.blockTableView.populate(self.currentSection.blockList)
             self.clearChordLineEdits()
             self.updateChordDict()