[Bug]: MaxInstancesExceededException Recurring events are only allowed to generate 3500 - Error cleaning up reminders of a calendar object

⚠️ 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

Similarly to #34442 I am encountering this issue since upgrading to Nextcloud 28 (I am not sure if it's a result of NC28 or a new calendar event). The data in the log is extremely limited and I cannot track down which event is causing this issue. The user in question has loads of events in the calendar and tracking down the issue is becoming complex.

The error appears multiple times a day.

Steps to reproduce

I cannot reliably reproduce this.

Expected behavior

No error

Installation method

Community Docker image

Nextcloud Server version

28

Operating system

Other

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?

Updated from a MINOR version (ex. 22.1 to 22.2)

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": {
        "instanceid": "***REMOVED SENSITIVE VALUE***",
        "passwordsalt": "***REMOVED SENSITIVE VALUE***",
        "secret": "***REMOVED SENSITIVE VALUE***",
        "trusted_domains": [
            "xxx.yyy.zzz"
        ],
        "datadirectory": "***REMOVED SENSITIVE VALUE***",
        "dbtype": "pgsql",
        "version": "28.0.2.5",
        "overwriteprotocol": "https",
        "overwrite.cli.url": "https:\/\/xxx.yyy.zzz\/",
        "htaccess.RewriteBase": "\/",
        "dbname": "***REMOVED SENSITIVE VALUE***",
        "dbhost": "***REMOVED SENSITIVE VALUE***",
        "dbport": "",
        "dbtableprefix": "oc_",
        "dbuser": "***REMOVED SENSITIVE VALUE***",
        "dbpassword": "***REMOVED SENSITIVE VALUE***",
        "installed": true,
        "memcache.distributed": "\\OC\\Memcache\\Redis",
        "memcache.local": "\\OC\\Memcache\\APCu",
        "memcache.locking": "\\OC\\Memcache\\Redis",
        "redis": {
            "host": "***REMOVED SENSITIVE VALUE***",
            "port": 6379,
            "timeout": 3
        },
        "mail_smtpmode": "smtp",
        "mail_smtpauth": 1,
        "mail_sendmailmode": "smtp",
        "mail_smtphost": "***REMOVED SENSITIVE VALUE***",
        "mail_smtpport": "587",
        "mail_smtpauthtype": "PLAIN",
        "mail_from_address": "***REMOVED SENSITIVE VALUE***",
        "mail_domain": "***REMOVED SENSITIVE VALUE***",
        "mail_smtpname": "***REMOVED SENSITIVE VALUE***",
        "mail_smtppassword": "***REMOVED SENSITIVE VALUE***",
        "maintenance": false,
        "theme": "",
        "loglevel": 3,
        "maintenance_window_start": 1,
        "updater.release.channel": "stable",
        "preview_max_x": "2048",
        "preview_max_y": "2048",
        "jpeg_quality": "60",
        "enable_previews": true,
        "enabledPreviewProviders": [
            "OC\\Preview\\Image",
            "OC\\Preview\\Movie",
            "OC\\Preview\\TXT",
            "OC\\Preview\\MarkDown",
            "OC\\Preview\\TIFF",
            "OC\\Preview\\HEIC"
        ],
        "lost_password_link": "disabled",
        "auth.webauthn.enabled": false,
        "default_phone_region": "IT",
        "trusted_proxies": "***REMOVED SENSITIVE VALUE***",
        "forwarded_for_headers": [
            "X-Forwarded-For",
            "HTTP_X_FORWARDED_FOR"
        ],
        "apps_paths": [
            {
                "path": "\/var\/www\/html\/apps",
                "url": "\/apps",
                "writable": false
            },
            {
                "path": "\/var\/www\/html\/custom_apps",
                "url": "\/custom_apps",
                "writable": true
            }
        ],
        "memories.exiftool": "\/var\/www\/html\/custom_apps\/memories\/bin-ext\/exiftool-amd64-glibc",
        "memories.vod.path": "\/var\/www\/html\/custom_apps\/memories\/bin-ext\/go-vod-amd64",
        "memories.vod.ffmpeg": "\/usr\/bin\/ffmpeg",
        "memories.vod.ffprobe": "\/usr\/bin\/ffprobe",
        "memories.gis_type": 2,
        "defaultapp": "files",
        "activity_expire_days": 365
    }
}

List of activated Apps

Enabled:
  - activity: 2.20.0
  - bruteforcesettings: 2.8.0
  - calendar: 4.6.5
  - cloud_federation_api: 1.11.0
  - comments: 1.18.0
  - contacts: 5.5.1
  - dav: 1.29.1
  - end_to_end_encryption: 1.14.1
  - federatedfilesharing: 1.18.0
  - files: 2.0.0
  - files_pdfviewer: 2.9.0
  - files_reminders: 1.1.0
  - files_sharing: 1.20.0
  - files_trashbin: 1.18.0
  - files_versions: 1.21.0
  - firstrunwizard: 2.17.0
  - impersonate: 1.15.0
  - logreader: 2.13.0
  - lookup_server_connector: 1.16.0
  - memories: 6.2.2
  - nextcloud_announcements: 1.17.0
  - notifications: 2.16.0
  - notify_push: 0.6.9
  - oauth2: 1.16.3
  - password_policy: 1.18.0
  - photos: 2.4.0
  - previewgenerator: 5.4.0
  - privacy: 1.12.0
  - provisioning_api: 1.18.0
  - recommendations: 2.0.0
  - related_resources: 1.3.0
  - serverinfo: 1.18.0
  - settings: 1.10.1
  - sharebymail: 1.18.0
  - side_menu: 3.11.7
  - snappymail: 2.34.2
  - support: 1.11.0
  - systemtags: 1.18.0
  - tasks: 0.15.0
  - text: 3.9.1
  - theming: 2.3.0
  - twofactor_backupcodes: 1.17.0
  - twofactor_totp: 10.0.0-beta.2
  - updatenotification: 1.18.0
  - user_status: 1.8.1
  - viewer: 2.2.0
  - workflowengine: 2.10.0
Disabled:
  - admin_audit: 1.18.0
  - circles: 28.0.0-dev (installed 27.0.1)
  - contactsinteraction: 1.9.0 (installed 1.2.0)
  - dashboard: 7.8.0 (installed 7.3.0)
  - encryption: 2.16.0
  - external: 5.3.1 (installed 5.3.1)
  - federation: 1.18.0 (installed 1.9.0)
  - files_external: 1.20.0
  - survey_client: 1.16.0 (installed 1.4.0)
  - suspicious_login: 6.0.0 (installed 5.0.0)
  - user_ldap: 1.19.0
  - weather_status: 1.8.0 (installed 1.0.0)

Nextcloud Signing status

No errors have been found.

Nextcloud Logs

{
  "reqId": "***",
  "level": 3,
  "time": "2024-02-18T17:00:22+00:00",
  "remoteAddr": "***",
  "user": "***",
  "app": "dav",
  "method": "PUT",
  "url": "/remote.php/dav/calendars/***/personal/***.ics",
  "message": "Error cleaning up reminders of a calendar object: Recurring events are only allowed to generate 3500",
  "userAgent": "iOS/17.2.1 dataaccessd/1.0",
  "version": "28.0.2.5",
  "exception": {
    "Exception": "Sabre\\VObject\\Recur\\MaxInstancesExceededException",
    "Message": "Recurring events are only allowed to generate 3500",
    "Code": 0,
    "Trace": [
      {
        "file": "/var/www/html/apps/dav/lib/CalDAV/Reminder/ReminderService.php",
        "line": 293,
        "function": "valid",
        "class": "Sabre\\VObject\\Recur\\EventIterator",
        "type": "->",
        "args": []
      },
      {
        "file": "/var/www/html/apps/dav/lib/CalDAV/Reminder/ReminderService.php",
        "line": 366,
        "function": "onCalendarObjectCreate",
        "class": "OCA\\DAV\\CalDAV\\Reminder\\ReminderService",
        "type": "->",
        "args": [
          [
            7718231,
            "*** sensitive parameters replaced ***",
            1708275622,
            "\"dc734f290912690b18d328cae6cf25e8\"",
            "*** sensitive parameters replaced ***",
            "And 5 more entries, set log level to debug to see all entries"
          ]
        ]
      },
      {
        "file": "/var/www/html/apps/dav/lib/Listener/CalendarObjectReminderUpdaterListener.php",
        "line": 138,
        "function": "onCalendarObjectEdit",
        "class": "OCA\\DAV\\CalDAV\\Reminder\\ReminderService",
        "type": "->",
        "args": [
          [
            7718231,
            "*** sensitive parameters replaced ***",
            1708275622,
            "\"dc734f290912690b18d328cae6cf25e8\"",
            "*** sensitive parameters replaced ***",
            "And 5 more entries, set log level to debug to see all entries"
          ]
        ]
      },
      {
        "file": "/var/www/html/lib/private/EventDispatcher/ServiceEventListener.php",
        "line": 86,
        "function": "handle",
        "class": "OCA\\DAV\\Listener\\CalendarObjectReminderUpdaterListener",
        "type": "->",
        "args": [
          [
            "OCA\\DAV\\Events\\CalendarObjectUpdatedEvent"
          ]
        ]
      },
      {
        "file": "/var/www/html/3rdparty/symfony/event-dispatcher/EventDispatcher.php",
        "line": 230,
        "function": "__invoke",
        "class": "OC\\EventDispatcher\\ServiceEventListener",
        "type": "->",
        "args": [
          [
            "OCA\\DAV\\Events\\CalendarObjectUpdatedEvent"
          ],
          "OCA\\DAV\\Events\\CalendarObjectUpdatedEvent",
          [
            "Symfony\\Component\\EventDispatcher\\EventDispatcher"
          ]
        ]
      },
      {
        "file": "/var/www/html/3rdparty/symfony/event-dispatcher/EventDispatcher.php",
        "line": 59,
        "function": "callListeners",
        "class": "Symfony\\Component\\EventDispatcher\\EventDispatcher",
        "type": "->",
        "args": [
          [
            [
              "Closure"
            ],
            [
              "Closure"
            ],
            [
              "Closure"
            ]
          ],
          "OCA\\DAV\\Events\\CalendarObjectUpdatedEvent",
          [
            "OCA\\DAV\\Events\\CalendarObjectUpdatedEvent"
          ]
        ]
      },
      {
        "file": "/var/www/html/lib/private/EventDispatcher/EventDispatcher.php",
        "line": 94,
        "function": "dispatch",
        "class": "Symfony\\Component\\EventDispatcher\\EventDispatcher",
        "type": "->",
        "args": [
          [
            "OCA\\DAV\\Events\\CalendarObjectUpdatedEvent"
          ],
          "OCA\\DAV\\Events\\CalendarObjectUpdatedEvent"
        ]
      },
      {
        "file": "/var/www/html/lib/private/EventDispatcher/EventDispatcher.php",
        "line": 106,
        "function": "dispatch",
        "class": "OC\\EventDispatcher\\EventDispatcher",
        "type": "->",
        "args": [
          "OCA\\DAV\\Events\\CalendarObjectUpdatedEvent",
          [
            "OCA\\DAV\\Events\\CalendarObjectUpdatedEvent"
          ]
        ]
      },
      {
        "file": "/var/www/html/apps/dav/lib/CalDAV/CalDavBackend.php",
        "line": 1338,
        "function": "dispatchTyped",
        "class": "OC\\EventDispatcher\\EventDispatcher",
        "type": "->",
        "args": [
          [
            "OCA\\DAV\\Events\\CalendarObjectUpdatedEvent"
          ]
        ]
      },
      {
        "file": "/var/www/html/lib/public/AppFramework/Db/TTransactional.php",
        "line": 63,
        "function": "OCA\\DAV\\CalDAV\\{closure}",
        "class": "OCA\\DAV\\CalDAV\\CalDavBackend",
        "type": "->",
        "args": [
          "*** sensitive parameters replaced ***"
        ]
      },
      {
        "file": "/var/www/html/apps/dav/lib/CalDAV/CalDavBackend.php",
        "line": 1312,
        "function": "atomic",
        "class": "OCA\\DAV\\CalDAV\\CalDavBackend",
        "type": "->",
        "args": [
          [
            "Closure"
          ],
          [
            "OC\\DB\\ConnectionAdapter"
          ]
        ]
      },
      {
        "file": "/var/www/html/3rdparty/sabre/dav/lib/CalDAV/CalendarObject.php",
        "line": 103,
        "function": "updateCalendarObject",
        "class": "OCA\\DAV\\CalDAV\\CalDavBackend",
        "type": "->",
        "args": [
          "*** sensitive parameters replaced ***"
        ]
      },
      {
        "file": "/var/www/html/3rdparty/sabre/dav/lib/DAV/Server.php",
        "line": 1137,
        "function": "put",
        "class": "Sabre\\CalDAV\\CalendarObject",
        "type": "->",
        "args": [
          "*** sensitive parameters replaced ***"
        ]
      },
      {
        "file": "/var/www/html/3rdparty/sabre/dav/lib/DAV/CorePlugin.php",
        "line": 492,
        "function": "updateFile",
        "class": "Sabre\\DAV\\Server",
        "type": "->",
        "args": [
          "*** sensitive parameters replaced ***"
        ]
      },
      {
        "file": "/var/www/html/3rdparty/sabre/event/lib/WildcardEmitterTrait.php",
        "line": 89,
        "function": "httpPut",
        "class": "Sabre\\DAV\\CorePlugin",
        "type": "->",
        "args": [
          [
            "Sabre\\HTTP\\Request"
          ],
          [
            "Sabre\\HTTP\\Response"
          ]
        ]
      },
      {
        "file": "/var/www/html/3rdparty/sabre/dav/lib/DAV/Server.php",
        "line": 472,
        "function": "emit",
        "class": "Sabre\\DAV\\Server",
        "type": "->",
        "args": [
          "method:PUT",
          [
            [
              "Sabre\\HTTP\\Request"
            ],
            [
              "Sabre\\HTTP\\Response"
            ]
          ]
        ]
      },
      {
        "file": "/var/www/html/3rdparty/sabre/dav/lib/DAV/Server.php",
        "line": 253,
        "function": "invokeMethod",
        "class": "Sabre\\DAV\\Server",
        "type": "->",
        "args": [
          [
            "Sabre\\HTTP\\Request"
          ],
          [
            "Sabre\\HTTP\\Response"
          ]
        ]
      },
      {
        "file": "/var/www/html/3rdparty/sabre/dav/lib/DAV/Server.php",
        "line": 321,
        "function": "start",
        "class": "Sabre\\DAV\\Server",
        "type": "->",
        "args": []
      },
      {
        "file": "/var/www/html/apps/dav/lib/Server.php",
        "line": 370,
        "function": "exec",
        "class": "Sabre\\DAV\\Server",
        "type": "->",
        "args": []
      },
      {
        "file": "/var/www/html/apps/dav/appinfo/v2/remote.php",
        "line": 35,
        "function": "exec",
        "class": "OCA\\DAV\\Server",
        "type": "->",
        "args": []
      },
      {
        "file": "/var/www/html/remote.php",
        "line": 172,
        "args": [
          "/var/www/html/apps/dav/appinfo/v2/remote.php"
        ],
        "function": "require_once"
      }
    ],
    "File": "/var/www/html/3rdparty/sabre/vobject/lib/Recur/EventIterator.php",
    "Line": 306,
    "message": "Error cleaning up reminders of a calendar object: Recurring events are only allowed to generate 3500",
    "exception": [],
    "CustomMessage": "Error cleaning up reminders of a calendar object: Recurring events are only allowed to generate 3500"
  },
  "id": "***"
}

Additional info

OS: Linux 6.1.74-Unraid x86_64

Start with apps/dav/lib/CalDAV/Reminder/ReminderService.php around lines 293 and 366, then follow CalendarObjectReminderUpdaterListener.php at line 138 and the reported calendar-object update flow. Investigate the recurring event that exceeds 3500 generated instances; done means reminder cleanup no longer emits the logged MaxInstancesExceededException.