[Bug]: When i try to process an event i get error Parse error: Invalid Mimedir file

[section1]

⚠️ This issue respects the following points: ⚠️

• This is a bug, not a question or a configuration/webserver/proxy issue.
• This issue is not already reported on Github OR Nextcloud Community Forum (I've searched it).
• Nextcloud Server is up to date. See Maintenance and Release Schedule for supported versions.
• I agree to follow Nextcloud's Code of Conduct.

Bug description

When ai try to accept some events(mostly coming from Outlook) i get an error and i can't accept it.
logs shows:
"This resource only supports valid iCalendar 2.0 data. Parse error: Invalid Mimedir file. Line starting at 40 did not follow iCalendar/vCard conventions"

Steps to reproduce

1.Someone with outlook send a meeting
2.I try to accept with Thunderbid and fails

Expected behavior

Accept the meet and see it in the NC calendar.

Installation method

Community Manual installation with Archive

Nextcloud Server version

28

Operating system

Debian/Ubuntu

Nextcloud Logs

{"reqId":"ANScfS8F8UcrDZFDrIHM","level":3,"time":"2024-05-29T19:26:31+00:00","remoteAddr":"172.x.x.x","user":"admin","app":"webdav","method":"PUT","url":"/remote.php/dav/calendars/admin/personal/XXXXXXXX-XXXX-XXXX-XXXX-XXXXXXXXXXXX.ics","message":"This resource only supports valid iCalendar 2.0 data. Parse error: Invalid Mimedir file. Line starting at 40 did not follow iCalendar/vCard conventions","userAgent":"Mozilla/5.0 (X11; Linux x86_64; rv:115.0) Gecko/20100101 Thunderbird/115.10.1","version":"28.0.6.1","exception":{"Exception":"Sabre\\DAV\\Exception\\UnsupportedMediaType","Message":"This resource only supports valid iCalendar 2.0 data. Parse error: Invalid Mimedir file. Line starting at 40 did not follow iCalendar/vCard conventions","Code":0,"Trace":[{"file":"/var/www/nextcloud/3rdparty/sabre/dav/lib/CalDAV/Plugin.php","line":766,"function":"validateICalendar","class":"Sabre\\CalDAV\\Plugin","type":"->"},{"file":"/var/www/nextcloud/3rdparty/sabre/event/lib/WildcardEmitterTrait.php","line":89,"function":"beforeCreateFile","class":"Sabre\\CalDAV\\Plugin","type":"->"},{"file":"/var/www/nextcloud/3rdparty/sabre/dav/lib/DAV/Server.php","line":1094,"function":"emit","class":"Sabre\\DAV\\Server","type":"->"},{"file":"/var/www/nextcloud/3rdparty/sabre/dav/lib/DAV/CorePlugin.php","line":504,"function":"createFile","class":"Sabre\\DAV\\Server","type":"->","args":["*** sensitive parameters replaced ***"]},{"file":"/var/www/nextcloud/3rdparty/sabre/event/lib/WildcardEmitterTrait.php","line":89,"function":"httpPut","class":"Sabre\\DAV\\CorePlugin","type":"->"},{"file":"/var/www/nextcloud/3rdparty/sabre/dav/lib/DAV/Server.php","line":472,"function":"emit","class":"Sabre\\DAV\\Server","type":"->"},{"file":"/var/www/nextcloud/3rdparty/sabre/dav/lib/DAV/Server.php","line":253,"function":"invokeMethod","class":"Sabre\\DAV\\Server","type":"->"},{"file":"/var/www/nextcloud/3rdparty/sabre/dav/lib/DAV/Server.php","line":321,"function":"start","class":"Sabre\\DAV\\Server","type":"->"},{"file":"/var/www/nextcloud/apps/dav/lib/Server.php","line":373,"function":"exec","class":"Sabre\\DAV\\Server","type":"->"},{"file":"/var/www/nextcloud/apps/dav/appinfo/v2/remote.php","line":35,"function":"exec","class":"OCA\\DAV\\Server","type":"->"},{"file":"/var/www/nextcloud/remote.php","line":172,"args":["/var/www/nextcloud/apps/dav/appinfo/v2/remote.php"],"function":"require_once"}],"File":"/var/www/nextcloud/3rdparty/sabre/dav/lib/CalDAV/Plugin.php","Line":806,"message":"This resource only supports valid iCalendar 2.0 data. Parse error: Invalid Mimedir file. Line starting at 40 did not follow iCalendar/vCard conventions","exception":{},"CustomMessage":"This resource only supports valid iCalendar 2.0 data. Parse error: Invalid Mimedir file. Line starting at 40 did not follow iCalendar/vCard conventions"}}

Additional info

This happens for example when the ICS file have an "_" in some parameter most of the time is: X-ENTOURAGE_UUID
I found this closed thread but still happens: #16679

[section1]

I add this FIX to NC version 28.0.6 and fix the problem with accepting an event with an underscore(_) ....and too tested using the import function in thunderbird and web calendar app and works perfectly.
Question: is a config option to enable OPTION_FORGIVING that i am missing ?

[Pofilo]

I had quite the same issue but the fix is not working for me.
However, I don't know how to figure out which event is a problem.
Everything in logs is blanked because considered as "sensitive data", how do you know which event is the source of the problem ?

I have the log every single time the calendar is synced (not when I try to accept an invitation):

UnsupportedMediaType This resource only supports valid iCalendar 2.0 data. Parse error: Invalid Mimedir file. Line starting at 30 did not follow iCalendar/vCard conventions

[section1]

@Pofilo check you access logs to see if you found a 5xx error (nginx/apache) and should show the ID of the meeting. example:
DELETE /remote.php/dav/calendars/USER/personal/dea11afd-2804-1bd3-9b98-35f529fcc528.ics HTTP/1.1" 500 ....

[Pofilo]

Thank you, I did not even think about that.
It's only 401 or 415 errors but I managed to find one ics file.

[section1]

Hi Devs, Can i add this fix in my instance ? nextcloud/3rdparty@ea0b8fd
I think there's no risk of this breaking anything ? inputs?