[Bug]: This recurrence rule does not generate any valid instances Unable to create calendar object from subscription

⚠️ 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

In one of my Google-calender subscriptions a appointment is causing this error, strangest is that the appointment IS in my calendar (perhaps an outdated, previous version of it)

Error generated in apps/dav/lib/CalDAV/WebcalCaching/RefreshWebcalService.php @ 131

Steps to reproduce

1. Wait for cron to reload subscriptions
2. See error appear

Expected behavior

No error about recurrence problems

Installation method

Official All-in-One appliance

Nextcloud Server version

29

Operating system

Debian/Ubuntu

PHP engine version

PHP 8.2

Web server

Apache (supported)

Database engine version

PostgreSQL

Is this bug present after an update or on a fresh install?

None

Are you using the Nextcloud Server Encryption module?

Encryption is Disabled

What user-backends are you using?

• Default user-backend (database)
• LDAP/ Active Directory
• SSO - SAML
• Other

Configuration report

{
    "system": {
        "one-click-instance": true,
        "one-click-instance.user-limit": 100,
        "memcache.local": "\\OC\\Memcache\\APCu",
        "default_phone_region": "NL",
        "apps_paths": [
            {
                "path": "\/var\/www\/html\/apps",
                "url": "\/apps",
                "writable": false
            },
            {
                "path": "\/var\/www\/html\/custom_apps",
                "url": "\/custom_apps",
                "writable": true
            }
        ],
        "check_data_directory_permissions": false,
        "memcache.distributed": "\\OC\\Memcache\\Redis",
        "memcache.locking": "\\OC\\Memcache\\Redis",
        "redis": {
            "host": "***REMOVED SENSITIVE VALUE***",
            "password": "***REMOVED SENSITIVE VALUE***",
            "port": 6379
        },
        "overwritehost": "cloud.rikmeijer.nl",
        "overwriteprotocol": "https",
        "passwordsalt": "***REMOVED SENSITIVE VALUE***",
        "secret": "***REMOVED SENSITIVE VALUE***",
        "trusted_domains": [
            "localhost",
            "cloud.rikmeijer.nl"
        ],
        "datadirectory": "***REMOVED SENSITIVE VALUE***",
        "dbtype": "pgsql",
        "version": "29.0.4.1",
        "overwrite.cli.url": "https:\/\/cloud.rikmeijer.nl\/",
        "dbname": "***REMOVED SENSITIVE VALUE***",
        "dbhost": "***REMOVED SENSITIVE VALUE***",
        "dbport": "",
        "dbtableprefix": "oc_",
        "dbuser": "***REMOVED SENSITIVE VALUE***",
        "dbpassword": "***REMOVED SENSITIVE VALUE***",
        "installed": true,
        "instanceid": "***REMOVED SENSITIVE VALUE***",
        "maintenance": false,
        "debug": false,
        "loglevel": "3",
        "log_type": "file",
        "logfile": "\/var\/www\/html\/data\/nextcloud.log",
        "log_rotate_size": "10485760",
        "log.condition": {
            "apps": [
                "admin_audit"
            ]
        },
        "preview_max_x": 2048,
        "preview_max_y": 2048,
        "jpeg_quality": 60,
        "enabledPreviewProviders": [
            "OC\\Preview\\Imaginary",
            "OC\\Preview\\MarkDown",
            "OC\\Preview\\MP3",
            "OC\\Preview\\TXT",
            "OC\\Preview\\OpenDocument",
            "OC\\Preview\\Movie",
            "OC\\Preview\\Krita"
        ],
        "enable_previews": true,
        "upgrade.disable-web": true,
        "mail_smtpmode": "smtp",
        "trashbin_retention_obligation": "auto, 30",
        "versions_retention_obligation": "auto, 30",
        "activity_expire_days": "30",
        "simpleSignUpLink.shown": false,
        "share_folder": "\/Shared",
        "one-click-instance.link": "https:\/\/nextcloud.com\/all-in-one\/",
        "upgrade.cli-upgrade-link": "https:\/\/github.com\/nextcloud\/all-in-one\/discussions\/2726",
        "updatedirectory": "\/nc-updater",
        "davstorage.request_timeout": 3600,
        "htaccess.RewriteBase": "\/",
        "dbpersistent": false,
        "files_external_allow_create_new_local": true,
        "trusted_proxies": "***REMOVED SENSITIVE VALUE***",
        "preview_imaginary_url": "***REMOVED SENSITIVE VALUE***",
        "mail_sendmailmode": "smtp",
        "mail_from_address": "***REMOVED SENSITIVE VALUE***",
        "mail_domain": "***REMOVED SENSITIVE VALUE***",
        "mail_smtphost": "***REMOVED SENSITIVE VALUE***",
        "mail_smtpport": "25",
        "twofactor_enforced": "true",
        "twofactor_enforced_groups": [
            "admin"
        ],
        "twofactor_enforced_excluded_groups": [
            "OpenProject"
        ],
        "appsallowlist": [],
        "allow_local_remote_servers": true,
        "updater.release.channel": "beta",
        "app_install_overwrite": [
            "nextcloud-aio",
            "printer",
            "talk_matterbridge"
        ],
        "maintenance_window_start": 100,
        "memories.exiftool": "\/var\/www\/html\/custom_apps\/memories\/bin-ext\/exiftool-aarch64-musl",
        "memories.vod.path": "\/var\/www\/html\/custom_apps\/memories\/bin-ext\/go-vod-aarch64",
        "memories.vod.ffmpeg": "\/usr\/bin\/ffmpeg",
        "memories.vod.ffprobe": "\/usr\/bin\/ffprobe",
        "preview_imaginary_key": "***REMOVED SENSITIVE VALUE***",
        "memories.db.triggers.fcu": true,
        "auth.bruteforce.protection.enabled": true,
        "ratelimit.protection.enabled": true,
        "memories.gis_type": 2
    }
}

List of activated Apps

Enabled:
  - activity: 2.21.1
  - admin_audit: 1.19.0
  - app_api: 3.1.0
  - bookmarks: 14.2.4
  - bruteforcesettings: 2.9.0
  - calendar: 4.7.15
  - circles: 29.0.0-dev
  - cloud_federation_api: 1.12.0
  - comments: 1.19.0
  - contacts: 6.0.0
  - contactsinteraction: 1.10.0
  - dashboard: 7.9.0
  - dav: 1.30.1
  - event_update_notification: 2.4.0
  - federatedfilesharing: 1.19.0
  - federation: 1.19.0
  - files: 2.1.0
  - files_downloadlimit: 2.0.0
  - files_external: 1.21.0
  - files_notify_redis: 0.3.4
  - files_pdfviewer: 2.10.0
  - files_reminders: 1.2.0
  - files_sharing: 1.21.0
  - files_trashbin: 1.19.0
  - files_versions: 1.22.0
  - firstrunwizard: 2.18.0
  - gpoddersync: 3.9.0
  - groupfolders: 17.0.2
  - integration_github: 2.0.7
  - integration_google: 3.0.2
  - integration_paperless: 1.0.3
  - logreader: 2.14.0
  - lookup_server_connector: 1.17.0
  - mail: 3.7.7
  - metadata: 0.20.0
  - news: 25.0.0-alpha8
  - nextcloud-aio: 0.6.0
  - nextcloud_announcements: 1.18.0
  - notes: 4.10.1
  - notifications: 2.17.0
  - notify_push: 0.7.0
  - oauth2: 1.17.0
  - oidc: 0.9.2
  - password_policy: 1.19.0
  - photos: 2.5.0
  - previewgenerator: 5.6.0
  - privacy: 1.13.0
  - provisioning_api: 1.19.0
  - recognize: 7.1.0
  - recommendations: 2.1.0
  - registration: 2.4.0
  - related_resources: 1.4.0
  - richdocuments: 8.4.4
  - serverinfo: 1.19.0
  - settings: 1.12.0
  - sharebymail: 1.19.0
  - sociallogin: 5.6.6
  - socialsharing_diaspora: 3.1.0
  - socialsharing_email: 3.1.0
  - socialsharing_twitter: 3.1.0
  - spreed: 19.0.7
  - support: 1.12.0
  - survey_client: 1.17.0
  - suspicious_login: 7.0.0
  - systemtags: 1.19.0
  - talk_matterbridge: 1.28.0-0
  - tasks: 0.16.1
  - text: 3.10.1
  - theming: 2.4.0
  - twofactor_admin: 4.5.0
  - twofactor_backupcodes: 1.18.0
  - twofactor_nextcloud_notification: 3.10.0
  - twofactor_totp: 11.0.0-dev
  - twofactor_webauthn: 1.4.0
  - user_status: 1.9.0
  - viewer: 2.3.0
  - weather_status: 1.9.0
  - workflowengine: 2.11.0
Disabled:
  - encryption: 2.17.0
  - user_ldap: 1.20.0

Nextcloud Signing status

No errors have been found.

Nextcloud Logs

{"reqId":"2z8n9cZ5co7s975yZwFM","level":3,"time":"2024-08-21T07:46:06+00:00","remoteAddr":"","user":"--","app":"dav","method":"","url":"--","message":"Unable to create calendar object from subscription 3"}

Additional info

Relevant ICS

BEGIN:VCALENDAR\r\nVERSION:2.0\r\nPRODID:-//Sabre//Sabre VObject 4.5.4//EN\r\nCALSCALE:GREGORIAN\r\nBEGIN:VTIMEZONE\r\nTZID:Europe/Paris\r\nX-LIC-LOCATION:Europe/Paris\r\nBEGIN:DAYLIGHT\r\nTZOFFSETFROM:+0100\r\nTZOFFSETTO:+0200\r\nTZNAME:GMT+2\r\nDTSTART:19700329T020000\r\nRRULE:FREQ=YEARLY;BYMONTH=3;BYDAY=-1SU\r\nEND:DAYLIGHT\r\nBEGIN:STANDARD\r\nTZOFFSETFROM:+0200\r\nTZOFFSETTO:+0100\r\nTZNAME:GMT+1\r\nDTSTART:19701025T030000\r\nRRULE:FREQ=YEARLY;BYMONTH=10;BYDAY=-1SU\r\nEND:STANDARD\r\nEND:VTIMEZONE\r\nBEGIN:VTIMEZONE\r\nTZID:Europe/Amsterdam\r\nX-LIC-LOCATION:Europe/Amsterdam\r\nBEGIN:DAYLIGHT\r\nTZOFFSETFROM:+0100\r\nTZOFFSETTO:+0200\r\nTZNAME:GMT+2\r\nDTSTART:19700329T020000\r\nRRULE:FREQ=YEARLY;BYMONTH=3;BYDAY=-1SU\r\nEND:DAYLIGHT\r\nBEGIN:STANDARD\r\nTZOFFSETFROM:+0200\r\nTZOFFSETTO:+0100\r\nTZNAME:GMT+1\r\nDTSTART:19701025T030000\r\nRRULE:FREQ=YEARLY;BYMONTH=10;BYDAY=-1SU\r\nEND:STANDARD\r\nEND:VTIMEZONE\r\nBEGIN:VTIMEZONE\r\nTZID:Europe/Brussels\r\nX-LIC-LOCATION:Europe/Brussels\r\nBEGIN:DAYLIGHT\r\nTZOFFSETFROM:+0100\r\nTZOFFSETTO:+0200\r\nTZNAME:GMT+2\r\nDTSTART:19700329T020000\r\nRRULE:FREQ=YEARLY;BYMONTH=3;BYDAY=-1SU\r\nEND:DAYLIGHT\r\nBEGIN:STANDARD\r\nTZOFFSETFROM:+0200\r\nTZOFFSETTO:+0100\r\nTZNAME:GMT+1\r\nDTSTART:19701025T030000\r\nRRULE:FREQ=YEARLY;BYMONTH=10;BYDAY=-1SU\r\nEND:STANDARD\r\nEND:VTIMEZONE\r\nBEGIN:VEVENT\r\nDTSTART;TZID=Europe/Brussels:20231229T130000\r\nDTEND;TZID=Europe/Brussels:20231229T133000\r\nRRULE:FREQ=WEEKLY;WKST=SU;UNTIL=20240111T225959Z;INTERVAL=2;BYDAY=FR\r\nEXDATE;TZID=Europe/Brussels:20231229T130000\r\nDTSTAMP:20240821T074537Z\r\nCENSOREDX-GOOGLE-CONFERENCE:https://meet.google.com/**CENSORED**\r\nCREATED:20230220T110458Z\r\nDESCRIPTION:Deelnemen via Google Meet: https://meet.google.com/**CENSORED**\r\n d\nOf bel: (NL) +31 20 257 3073 Pincode: CENSORED#\nMeer telefoonnummers:\r\n https://tel.meet/**CENSORED**?pin=**CENSORED**&hs=7\\n\\nGa voor meer info\r\n rmatie over Meet naar https://support.google.com/a/users/answer/9282720\r\nLAST-MODIFIED:20240816T133846Z\r\nSEQUENCE:3\r\nSTATUS:CONFIRMED\r\nSUMMARY:**CENSORED**\r\nTRANSP:OPAQUE\r\nEND:VEVENT\r\nEND:VCALENDAR\r\n"},"id":"66c59b4330309"}

Start in apps/dav/lib/CalDAV/WebcalCaching/RefreshWebcalService.php around line 131 and inspect how the supplied ICS recurrence rule is processed during cron subscription refresh. Reproduce the failure with the provided event and confirm whether the calendar object can be created without the logged error. Done means the subscription refresh handles this recurrence data without emitting the error.