[Bug]: Updater is interrupted right after backup.

⚠️ 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

Almost every time I update the version of Nextcloud, it interrupts after backup. This time, I reloaded the page as nothing else worked. An update secret was asked for. I do not know what it means. So I went back to the application and restarted the update process which went fine once again.

Steps to reproduce

1. Have an outdated version!
2. Go for the update!
3. See that it break first right after the backup!

Expected behavior

The update works fine.

Nextcloud Server version

30

Operating system

Debian/Ubuntu

PHP engine version

PHP 8.3

Web server

Apache (supported)

Database engine version

MariaDB

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

Updated from a MINOR version (ex. 32.0.1 to 32.0.2)

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***",
        "overwrite.cli.url": "https:\/\/nextcloud.ons.ee\/",
        "overwriteprotocol": "https",
        "htaccess.RewriteBase": "\/",
        "passwordsalt": "***REMOVED SENSITIVE VALUE***",
        "secret": "***REMOVED SENSITIVE VALUE***",
        "trusted_domains": [
            "nextcloud.ons.ee"
        ],
        "trusted_proxies": "***REMOVED SENSITIVE VALUE***",
        "datadirectory": "***REMOVED SENSITIVE VALUE***",
        "dbtype": "mysql",
        "version": "31.0.9.1",
        "dbname": "***REMOVED SENSITIVE VALUE***",
        "dbhost": "***REMOVED SENSITIVE VALUE***",
        "dbport": "",
        "dbtableprefix": "oc_",
        "mysql.utf8mb4": true,
        "dbuser": "***REMOVED SENSITIVE VALUE***",
        "dbpassword": "***REMOVED SENSITIVE VALUE***",
        "installed": true,
        "mail_from_address": "***REMOVED SENSITIVE VALUE***",
        "mail_smtpmode": "smtp",
        "mail_sendmailmode": "smtp",
        "mail_domain": "***REMOVED SENSITIVE VALUE***",
        "mail_smtphost": "***REMOVED SENSITIVE VALUE***",
        "mail_smtpport": "587",
        "mail_smtpauth": 1,
        "mail_smtpname": "***REMOVED SENSITIVE VALUE***",
        "mail_smtppassword": "***REMOVED SENSITIVE VALUE***",
        "memcache.local": "\\OC\\Memcache\\Redis",
        "filelocking.enabled": true,
        "memcache.distributed": "\\OC\\Memcache\\Redis",
        "memcache.locking": "\\OC\\Memcache\\Redis",
        "redis": {
            "host": "***REMOVED SENSITIVE VALUE***",
            "port": 6379,
            "timeout": 0,
            "dbindex": 0
        },
        "default_phone_region": "EE",
        "app_install_overwrite": {
            "0": "weather",
            "3": "multiboards",
            "4": "health",
            "5": "gpxmotion",
            "6": "gpxedit",
            "7": "drawio"
        },
        "maintenance": false,
        "theme": "",
        "loglevel": 2,
        "default_timezone": "Europe\/Tallinn",
        "auth.bruteforce.protection.enabled": false,
        "debug": false,
        "spreed": {
            "signaling_server": "http:\/\/127.0.0.1:8080",
            "shared_secret": "supersecret"
        },
        "collaboration.server.websocket.url": "wss:\/\/ons.ee\/ws"
    }
}

List of activated Apps

Enabled:
  - activity: 4.0.0
  - admin_audit: 1.21.0
  - app_api: 5.0.2
  - bruteforcesettings: 4.0.0
  - calendar: 5.5.3
  - circles: 31.0.0
  - cloud_federation_api: 1.14.0
  - comments: 1.21.0
  - contacts: 7.3.0
  - contactsinteraction: 1.12.0
  - dashboard: 7.11.0
  - dav: 1.33.0
  - deck: 1.15.2
  - drawio: 3.1.0
  - federatedfilesharing: 1.21.0
  - federation: 1.21.0
  - files: 2.3.1
  - files_downloadlimit: 4.0.0
  - files_emailviewer: 0.1.4
  - files_pdfviewer: 4.0.0
  - files_reminders: 1.4.0
  - files_sharing: 1.23.1
  - files_trashbin: 1.21.0
  - files_versions: 1.24.0
  - firstrunwizard: 4.0.0
  - forms: 5.1.2
  - gpxpod: 7.0.4
  - groupfolders: 19.1.3
  - health: 2.2.2
  - integration_openproject: 2.9.2
  - logreader: 4.0.0
  - lookup_server_connector: 1.19.0
  - mail: 5.4.0
  - nextcloud_announcements: 3.0.0
  - notes: 4.12.3
  - notifications: 4.0.0
  - oauth2: 1.19.1
  - onlyoffice: 9.10.0
  - password_policy: 3.0.0
  - photos: 4.0.0
  - privacy: 3.0.0
  - profile: 1.0.0
  - provisioning_api: 1.21.0
  - recommendations: 4.0.0
  - registration: 2.8.0
  - related_resources: 2.0.0
  - serverinfo: 3.0.0
  - settings: 1.14.0
  - sharebymail: 1.21.0
  - spreed: 21.1.4
  - support: 3.0.0
  - survey_client: 3.0.0
  - systemtags: 1.21.1
  - tables: 0.9.5
  - tasks: 0.16.1
  - text: 5.0.0
  - theming: 2.6.1
  - twofactor_backupcodes: 1.20.0
  - updatenotification: 1.21.0
  - user_status: 1.11.0
  - viewer: 4.0.0
  - weather_status: 1.11.0
  - webhook_listeners: 1.2.0
  - workflowengine: 2.13.0
Disabled:
  - encryption: 2.19.0
  - files_external: 1.23.0
  - files_rightclick: 0.15.1 (installed 1.6.0)
  - maps: 1.6.0 (installed 1.6.0)
  - recognize: 9.0.7 (installed 9.0.7)
  - suspicious_login: 9.0.1
  - twofactor_nextcloud_notification: 5.0.0
  - twofactor_totp: 13.0.0-dev.0
  - user_ldap: 1.22.0
  - weather: 1.7.7
  - whiteboard: 1.2.0 (installed 1.2.0)

Nextcloud Signing status

No errors have been found.

Nextcloud Logs

{"reqId":"iDgMRN0Sssx4aWnHUt2b","level":3,"time":"2025-09-15T20:50:51+00:00","remoteAddr":"192.168.1.1","user":"peacecop kalmer","app":"index","method":"GET","url":"/apps/theming/favicon/settings?v=91ca51a3","message":"Exception thrown: OCP\\Files\\GenericFileException","userAgent":"Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/139.0.0.0 Safari/537.36","version":"31.0.9.1","exception":{"Exception":"OCP\\Files\\GenericFileException","Message":"","Code":0,"Trace":[{"file":"/srv/nextcloud/lib/private/Files/SimpleFS/SimpleFile.php","line":55,"function":"getContent","class":"OC\\Files\\Node\\File","type":"->"},{"file":"/srv/nextcloud/lib/public/AppFramework/Http/FileDisplayResponse.php","line":51,"function":"getContent","class":"OC\\Files\\SimpleFS\\SimpleFile","type":"->"},{"file":"/srv/nextcloud/lib/private/AppFramework/App.php","line":218,"function":"callback","class":"OCP\\AppFramework\\Http\\FileDisplayResponse","type":"->"},{"file":"/srv/nextcloud/lib/private/Route/Router.php","line":315,"function":"main","class":"OC\\AppFramework\\App","type":"::"},{"file":"/srv/nextcloud/lib/base.php","line":1063,"function":"match","class":"OC\\Route\\Router","type":"->"},{"file":"/srv/nextcloud/index.php","line":24,"function":"handleRequest","class":"OC","type":"::"}],"File":"/srv/nextcloud/lib/private/Files/Node/File.php","Line":35,"message":"","exception":[],"CustomMessage":"Exception thrown: OCP\\Files\\GenericFileException"},"id":"68c87c3fb0046"}

Additional info

No response

Start by reproducing the update interruption and inspect the updater's logs around the backup and update-secret prompt; the report provides no updater source file or test entry point. The only referenced trace is in /srv/nextcloud/lib/private/Files/SimpleFS/SimpleFile.php, which may be incidental. Done means identifying a reliable failure cause and verifying that the update completes without interruption.