ERROR (SyncWorker_19) [root] Ical data was modified to avoid compatibility issues

[leeh11]

HA Core : 2024.1.4
ics_calendar: 4.2.0

After installing the integration and restarting, the calendar can be displayed normally, but the calendar data will not be displayed after a few minutes. The log reports the following error:

2024-01-20 21:33:44.143 ERROR (SyncWorker_19) [root] Ical data was modified to avoid compatibility issues
(Your calendar server breaks the icalendar standard)
This is probably harmless, particularly if not editing events or tasks
(error count: 4 - this error is ratelimited)
NoneType: None
2024-01-20 21:33:44.144 ERROR (SyncWorker_19) [root] --- 
+++