ICS calendar error: required key not provided @ data['summary']

[smartmatic]

Home Assistant Setup
Please indicate your version of HA and how it is installed.

Version: 2025.2.5

Installation Type (put an X between the square brackets for your HA):
[x] Home Assistant OS
[] Home Assistant Supervised
[] Home Assistant Container
[] Home Assistant Core

Hardware platform:
[] ARM
[] x86-64

Are you running in a container environment like Docker or Kubernetes?
[] Yes
[x] No

If running in a container, how is your image built?
[] Official HA container image
[] Official HA container image with customizations
[] Custom built container image

Describe the bug
Suddenly the calendar is no longer available and i get this error:
ICS Version: 5.1.3

Dieser Fehler stammt von einer benutzerdefinierten Integration

Logger: custom_components.ics_calendar.calendar
Quelle: custom_components/ics_calendar/calendar.py:345
Integration: ICS-Kalender (Dokumentation, Probleme)
Erstmals aufgetreten: 13:54:37 (12 Vorkommnisse)
Zuletzt protokolliert: 14:05:36

update: Abfall: Failed to parse ICS!
Traceback (most recent call last):
  File "/usr/src/homeassistant/homeassistant/components/calendar/__init__.py", line 386, in __post_init__
    CALENDAR_EVENT_SCHEMA(dataclasses.asdict(self, dict_factory=skip_none))
    ~~~~~~~~~~~~~~~~~~~~~^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/usr/local/lib/python3.13/site-packages/voluptuous/schema_builder.py", line 205, in __call__
    return self._compiled([], data)
           ~~~~~~~~~~~~~~^^^^^^^^^^
  File "/usr/local/lib/python3.13/site-packages/voluptuous/validators.py", line 256, in _run
    return self._exec(self._compiled, value, path)
           ~~~~~~~~~~^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/usr/local/lib/python3.13/site-packages/voluptuous/validators.py", line 386, in _exec
    raise e if self.msg is None else AllInvalid(self.msg, path=path)
  File "/usr/local/lib/python3.13/site-packages/voluptuous/validators.py", line 384, in _exec
    v = func(path, v)
  File "/usr/local/lib/python3.13/site-packages/voluptuous/schema_builder.py", line 549, in validate_dict
    return base_validate(path, data.items(), out)
  File "/usr/local/lib/python3.13/site-packages/voluptuous/schema_builder.py", line 382, in validate_mapping
    raise er.MultipleInvalid(errors)
voluptuous.error.MultipleInvalid: required key not provided @ data['summary']

The above exception was the direct cause of the following exception:

Traceback (most recent call last):
  File "/config/custom_components/ics_calendar/calendar.py", line 345, in async_update
    self.event = self.parser.get_current_event(
                 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^
        include_all_day=self.include_all_day,
        ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    ...<2 lines>...
        offset_hours=self._offset_hours,
        ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    )
    ^
  File "/config/custom_components/ics_calendar/parsers/parser_rie.py", line 143, in get_current_event
    return CalendarEvent(
        summary=temp_event.get("SUMMARY"),
    ...<3 lines>...
        description=temp_event.get("DESCRIPTION"),
    )
  File "<string>", line 11, in __init__
  File "/usr/src/homeassistant/homeassistant/components/calendar/__init__.py", line 388, in __post_init__
    raise HomeAssistantError(
        f"Failed to validate CalendarEvent: {err}"
    ) from err
homeassistant.exceptions.HomeAssistantError: Failed to validate CalendarEvent: required key not provided @ data['summary']

The strange thing is that the exact calendar and runs in my test system without issues with ics 5.1.3

[franc6]

What’s the difference between your test system and the one where you see this error?

At first glance, it looks like the install for this integration is corrupted, as it should be setting something for the summary all the time. It could be a bug in that logic, though, as I did make some changes about it recently. Is the test system a new install and configuration while the other is not new? If so, does removing the calendar and adding it back make it work? The answers will help me determine if it’s a bug and where.

Thanks!

[smartmatic]

Is the test system a new install and configuration while the other is not new?

No, the test system runs already for a longer time but my test system is a VM and my prod system a HA Yellow. I assume this difference does hot have any effect.

If so, does removing the calendar and adding it back make it work?
I tried it but unfortunately it does not solve it.

Is there something else i can check or try?