SHould be nearly working, but crashes on saving edited entry

urls.py

@@ -55,6 +55,7 @@ from troggle.core.views.logbooks import (
     logbookentry,
     logentrydelete,
     logreport,
+    logbookfile,
     notablepersons,
     people_ids,
     person,
@@ -244,6 +245,7 @@ trogglepatterns = [
     path('logbook_entries/<slug:year>', logbook_entries_export, name='logbook_entries_export'), 
     path('logreport/<slug:year>', logreport, name='logreport'), 
     path('logentrydelete/<slug:year>', logentrydelete, name='logentrydelete'), 
+    path('logbookfile/<slug:year>', logbookfile, name='logbookfile'), 
    
 #   Internal. editfile.html template uses these internally
     re_path(r'^getPeople/(?P<expeditionslug>.*)', get_people, name = "get_people"),