fix

hosts/www/caldav-export.py

@@ -45,7 +45,18 @@ def export_calendar(url: str, username: str, password: str, calendar: str) -> Ca
     print(f"  {len(objects)} objects")
 
     for obj in objects:
-        cal = Calendar.from_ical(obj.data)
+        data = obj.data
+
+        if data is None:
+            print(f"  fetching {obj.url}")
+            obj.load()
+            data = obj.data
+
+        if not data:
+            print(f"  skipping empty object {obj.url}")
+            continue
+
+        cal = Calendar.from_ical(data)
 
         for component in cal.walk():
             if component.name != "VCALENDAR":