Office365 ics file download stopped working, might need a different User Agent header

[siebert]

The integration fails to download a shared Office365 ics file. Apparently Microsoft is now more strict evaluating the User Agent Header, see this discussion for an Android App which also now fails with the same link:

bitfireAT/icsx5#654

Here is the error from the HASS log file:

============ ICS Integration Error ================
2025-08-20 09:57:36.649 ERROR (MainThread) [custom_components.ics.sensor] unfortunately ICS hit an error, please open a ticket at
2025-08-20 09:57:36.649 ERROR (MainThread) [custom_components.ics.sensor] https://github.com/KoljaWindeler/ics/issues
2025-08-20 09:57:36.649 ERROR (MainThread) [custom_components.ics.sensor] and paste the following output:
2025-08-20 09:57:36.650 ERROR (MainThread) [custom_components.ics.sensor] Traceback (most recent call last):
File "/usr/local/lib/python3.13/site-packages/icalendar/parser.py", line 326, in parts
validate_token(name)
~~~~~~~~~~~~~~^^^^^^
File "/usr/local/lib/python3.13/site-packages/icalendar/parser.py", line 115, in validate_token
raise ValueError(name)
ValueError:
During handling of the above exception, another exception occurred:
Traceback (most recent call last):
File "/config/custom_components/ics/sensor.py", line 179, in get_data
cal = Calendar.from_ical(cal_string)
File "/usr/local/lib/python3.13/site-packages/icalendar/cal.py", line 410, in from_ical
name, params, vals = line.parts()
~~~~~~~~~~^^
File "/usr/local/lib/python3.13/site-packages/icalendar/parser.py", line 340, in parts
raise ValueError(
f"Content line could not be parsed into parts: '{self}': {exc}")
ValueError: Content line could not be parsed into parts: '':
2025-08-20 09:57:36.650 ERROR (MainThread) [custom_components.ics.sensor]
thanks, Kolja

[mixedbreed]

Hello, I'm experiencing the same fault with download of ics file.
Hope you can look into it, since we have made us dependent of this solution in our family.

Best regards
Mixedbreed

[KoljaWindeler]

hi, try the newest beta version.
There is a field now during the config flow to change the user agent

[mixedbreed]

Hi and thanks for your effort.
I'm trying to add the new ics integration but the following error message:
The downloaded file can not be parsed, not a valid ICS file.
It worked previous with no extra configuration, just the url for ics download and an id.

Would appreciate your help figuring it out.

BR

[michelnet]

Hi Thanks for your effort. It works again. With the default agent it does not work. i changed to Mozilla/5.0 (X11; Linux x86_64; rv:38.0) Gecko/20100101 Thunderbird/38.2.0 Lightning/4.0.2 . after this change evening worked like before.

[mixedbreed]

Hi Thanks for your effort. It works again. With the default agent it does not work. i changed to Mozilla/5.0 (X11; Linux x86_64; rv:38.0) Gecko/20100101 Thunderbird/38.2.0 Lightning/4.0.2 . after this change evening worked like before.

Thanks to you both, worked after change of default agent.

[RonnieDilli]

The beta works with the supplied agent

Mozilla/5.0 (X11; Linux x86_64; rv:38.0) Gecko/20100101 Thunderbird/38.2.0 Lightning/4.0.2

Should put it on the the final release.