Nextcloud AIO freeze in browser

vincitus · September 24, 2026, 9:53am

Hey, I noticed the following issue: When being on my Nextcloud site and I open a photo in SofortUpload where I sync my Smartphone files to, the site is unresponsive and hogs local cpu for about 7 seconds before I can do anything else (close photo, view next photo etc). The issue is related to the amount of files in a folder (there are 20gb of photos/videos in my folder, the issue is not noticeable in folders with only three photos). So, I assume that some script loops through all files doing something.

The problem persists since many AIO versions (I currently run AIO v14.1.1, Nextcloud Hub 26 Winter 33.0.8) and for at least several months and across many versions of different browsers (firefox, thorium (chrome)). It seems to be a client side issue, the server does not freeze or hog server cpu.

Anyone else having this problem? Could a dev maybe fix this?

Cheers, vincitus

JimmyKater · September 24, 2026, 11:37am

maxybe you want to enlighten the forum with some more data that you would put in to the support template?

vincitus · September 24, 2026, 2:54pm

Sorry for not following protocol, here ya go:

The Basics

Nextcloud Server version: Nextcloud Hub 26 Winter 33.0.8
Operating system and version: Debian GNU/Linux 13.6 (trixie) x86_64 kernel 6.12.101+deb13-amd64 (in a qemu vm that lives inside another Debian GNU/Linux 13.6 (trixie) x86_64)
Web server and version: whichever runs in docker AIO, apache?
Reverse proxy and version: Nginx 1.30.4-1~bookworm
PHP version: 8.4.25
Is this the first time you’ve seen this error? No.
When did this problem seem to first start? I noticed it at least several months ago, it might exist for much longer. It only happens sometimes, quite indeterministically.
Installation method: AIO
Are you using Cloudflare, mod_security, or similar? No.

Steps to replicate it (hint: details matter!):

Open large folder (mine has 2787 files) of pictures and videos in nextcloud interface.
Click on one picture. Picture opens.
Click on x to close
Then sometimes, not always, site freezes for about 7 seconds while hogging CPU, and browser complains about the site slowing down the browser and offers to stop whatever is running.
Site unfreezes without me actively stopping it and can be used normally now until the next freeze

I do not want to be a hindrance to anyones enlightenment, but do not feel comfortable to post nextcloud.log at this time.

However, here is some anonymized browser (Firefox) console output at the time of the issue happening:

[ERROR] viewer: Could not register handler 
Object { app: "viewer", uid: "user", level: 2, error: "The handler is already registered", handler: {…} }
index.mjs:47:17
Initializing unified search plugin-filters from talk search.js:22:10
Notifications permissions not yet requested NotificationsApp.vue:564:12
Has notify_push enabled, slowing polling to 15 minutes NotificationsApp.vue:267:12
Polling interval updated to 900000 NotificationsApp.vue:510:12
Started background fetcher as session_keepalive is enabled NotificationsApp.vue:360:13
Got notification data, restoring default polling interval. NotificationsApp.vue:466:13
Sicherheitsfehler: Inhalt auf https://site.net/apps/files/files/63550?dir=%2FSofortUpload%2FCamera darf file:/// nicht laden oder verlinken.
Content-Security-Policy: Die Einstellungen der Seite haben das Laden einer Ressource (default-src) auf https://site.net/apps/files/files/63550?dir=%2FSofortUpload%2FCamera blockiert, da sie gegen folgende Direktive verstößt: "default-src 'none'" NetUtil.sys.mjs:142:15
Content-Security-Policy: Die Einstellungen der Seite haben das Laden einer Ressource (default-src) auf https://site.net/core/l10n/de.js?v=9f87ccdd-0 blockiert, da sie gegen folgende Direktive verstößt: "default-src 'none'" NetUtil.sys.mjs:142:15
Content-Security-Policy: Die Einstellungen der Seite haben das Laden einer Ressource (default-src) auf https://site.net/apps/comments/l10n/de.js?v=9f87ccdd-0 blockiert, da sie gegen folgende Direktive verstößt: "default-src 'none'" NetUtil.sys.mjs:142:15
[WARN] viewer: No files provided, skipping update 
Object { app: "viewer", uid: "user", level: 2 }
index.mjs:44:17
File info for /SofortUpload/Camera/20260717_152301.mp4 fetched 
Object { filename: "/SofortUpload/Camera/20260717_152301.mp4", basename: "20260717_152301.mp4", lastmod: "Fri, 17 Jul 2026 13:25:50 GMT", size: 176315977, type: "file", etag: "c3975e3e12c74e2761e8832cdf9bd082", mime: "video/mp4", tags: "", getcontentlength: 176315977, getcontenttype: "video/mp4", … }
Viewer.vue:666:1
[WARN] viewer: No files provided, skipping update 
Object { app: "viewer", uid: "user", level: 2 }
index.mjs:44:17
[WARN] viewer: No files provided, skipping update 
Object { app: "viewer", uid: "user", level: 2 }
index.mjs:44:17
File info for /SofortUpload/Camera/20260715_170928.jpg fetched 
Object { filename: "/SofortUpload/Camera/20260715_170928.jpg", basename: "20260715_170928.jpg", lastmod: "Wed, 15 Jul 2026 15:09:28 GMT", size: 4065586, type: "file", etag: "cd37e48a1be7be7d39984795289735c3", mime: "image/jpeg", tags: "", getcontentlength: 4065586, getcontenttype: "image/jpeg", … }
Viewer.vue:666:1
[WARN] viewer: No files provided, skipping update 
Object { app: "viewer", uid: "user", level: 2 }
index.mjs:44:17
[WARN] viewer: No files provided, skipping update 
Object { app: "viewer", uid: "user", level: 2 }
index.mjs:44:17
File info for /SofortUpload/Camera/20260715_170927.jpg fetched 
Object { filename: "/SofortUpload/Camera/20260715_170927.jpg", basename: "20260715_170927.jpg", lastmod: "Wed, 15 Jul 2026 15:09:27 GMT", size: 4662283, type: "file", etag: "d9523454ad7d10400e697835b2231d0e", mime: "image/jpeg", tags: "", getcontentlength: 4662283, getcontenttype: "image/jpeg", … }
Viewer.vue:666:1
[WARN] viewer: No files provided, skipping update 
Object { app: "viewer", uid: "user", level: 2 }

Configuration

Nextcloud

{
    "system": {
        "one-click-instance": true,
        "one-click-instance.user-limit": 100,
        "memcache.local": "\\OC\\Memcache\\APCu",
        "apps_paths": [
            {
                "path": "\/var\/www\/html\/apps",
                "url": "\/apps",
                "writable": false
            },
            {
                "path": "\/var\/www\/html\/custom_apps",
                "url": "\/custom_apps",
                "writable": true
            }
        ],
        "appsallowlist": false,
        "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,
            "timeout": 3,
            "read_timeout": 10
        },
        "overwritehost": "site.invalid",
        "overwriteprotocol": "https",
        "passwordsalt": "***REMOVED SENSITIVE VALUE***",
        "secret": "***REMOVED SENSITIVE VALUE***",
        "trusted_domains": [
            "localhost",
            "site.invalid"
        ],
        "datadirectory": "***REMOVED SENSITIVE VALUE***",
        "dbtype": "pgsql",
        "version": "34.0.4.1",
        "overwrite.cli.url": "https:\/\/site.invalid\/",
        "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,
        "updatedirectory": "\/nc-updater",
        "loglevel": 2,
        "loglevel": 2,
        "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": {
            "1": "OC\\Preview\\Image",
            "2": "OC\\Preview\\MarkDown",
            "3": "OC\\Preview\\MP3",
            "4": "OC\\Preview\\TXT",
            "5": "OC\\Preview\\OpenDocument",
            "6": "OC\\Preview\\Movie",
            "7": "OC\\Preview\\Krita",
            "0": "OC\\Preview\\Imaginary",
            "23": "OC\\Preview\\ImaginaryPDF"
        },
        "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",
        "maintenance_window_start": 100,
        "allow_local_remote_servers": true,
        "davstorage.request_timeout": 86400,
        "htaccess.RewriteBase": "\/",
        "dbpersistent": false,
        "auth.bruteforce.protection.enabled": true,
        "ratelimit.protection.enabled": true,
        "files_external_allow_create_new_local": true,
        "trusted_proxies": "***REMOVED SENSITIVE VALUE***",
        "preview_imaginary_url": "***REMOVED SENSITIVE VALUE***",
        "preview_imaginary_key": "***REMOVED SENSITIVE VALUE***",
        "twofactor_enforced": "false",
        "twofactor_enforced_groups": [
            "admin"
        ],
        "twofactor_enforced_excluded_groups": [],
        "documentation_url.server_logs": "https:\/\/github.com\/nextcloud\/all-in-one\/discussions\/5425",
        "updatechecker": false,
        "onlyoffice": {
            "jwt_secret": "***REMOVED SENSITIVE VALUE***",
            "jwt_header": "AuthorizationJwt"
        },
        "serverid": 445,
        "log_type_audit": "file",
        "logfile_audit": "\/var\/www\/html\/data\/audit.log",
        "update_channel": "stable",
        "default_phone_region": "AT",
        "DOMAIN": "site.invalid",
        "AIO_VERSION": "v14.1.1"
    }
}

Apps

Enabled:
  - activity: 7.0.0
  - admin_audit: 1.24.0
  - appstore: 1.0.0
  - bruteforcesettings: 7.0.0
  - calendar: 6.6.1
  - circles: 34.0.0
  - cloud_federation_api: 1.18.0
  - comments: 1.24.0
  - contacts: 8.9.0
  - contactsinteraction: 1.15.0
  - dashboard: 7.14.0
  - dav: 1.40.0
  - deck: 1.18.5
  - federatedfilesharing: 1.24.0
  - federation: 1.24.0
  - files: 2.6.0
  - files_downloadlimit: 5.2.0
  - files_external: 1.26.0
  - files_lock: 34.0.1
  - files_pdfviewer: 7.0.0
  - files_reminders: 1.7.0
  - files_sharing: 1.26.0
  - files_trashbin: 1.24.0
  - files_versions: 1.27.0
  - firstrunwizard: 7.0.0-dev.0
  - logreader: 7.0.0
  - lookup_server_connector: 1.22.0
  - nextcloud-aio: 0.9.0
  - nextcloud_announcements: 6.0.0
  - notes: 6.1.0
  - notifications: 7.0.0-dev.1
  - notify_push: 1.4.1
  - oauth2: 1.22.0
  - office: 1.0.0
  - password_policy: 6.0.0-dev.0
  - photos: 7.0.0
  - privacy: 6.0.0-dev.1
  - profile: 1.3.0
  - provisioning_api: 1.24.0
  - recommendations: 7.0.0
  - related_resources: 5.0.0-dev.0
  - richdocuments: 11.1.1
  - serverinfo: 6.0.0
  - settings: 1.17.0
  - sharebymail: 1.24.0
  - spreed: 24.0.5
  - support: 6.0.0
  - survey_client: 6.0.0-dev.0
  - systemtags: 1.24.0
  - tasks: 0.18.1
  - tasks: 0.18.1
  - text: 8.0.0
  - theming: 2.9.0
  - twofactor_backupcodes: 1.23.0
  - twofactor_totp: 16.0.0
  - twofactor_webauthn: 2.7.1
  - updatenotification: 1.24.0
  - user_status: 1.14.0
  - viewer: 7.0.0-dev.0
  - weather_status: 1.14.0
  - webhook_listeners: 1.6.0
  - whiteboard: 2.0.0
  - workflowengine: 2.16.0
Disabled:
  - app_api: 34.0.0 (installed 4.0.5)
  - encryption: 2.22.0
  - suspicious_login: 12.0.0-dev.0
  - twofactor_nextcloud_notification: 8.0.0
  - user_ldap: 1.25.0

My reason for posting this issue is less that I want anyone to fix my personal issues and more to bring this to attention, if I am not the only one experiencing it, so it can be fixed for everyone and nextcloud as a whole improves.

Thanks in advance for your time!

jtr · September 25, 2026, 7:20pm

See AIO’ How to run OCC commands

vincitus · September 26, 2026, 9:11am

Thanks a lot for the link! I edited my post above to contain the Nextcloud config and app list.

jtr · September 26, 2026, 9:35pm

After reading your post I ran across this Issue which seems relevant and has a update on it:

github.com/nextcloud/viewer

Viewer freezes the whole browser tab when opening a photo from a folder with thousands of images

opened 07:53PM - 17 Jun 26 UTC

Kuvwert

bug 0. Needs triage

**Describe the bug** Opening a photo in the viewer from a folder with a lot of i…mages (mine has around 8000) freezes the whole browser tab for about 20 seconds. The image actually shows up first and looks fine, then everything locks and Firefox pops the "a web page is slowing down your browser" warning. It comes back if I wait it out, but its rough. Folders with only a few files open instantly, so it definitly scales with the file count. **To Reproduce** Steps to reproduce the behavior: 1. Put a few thousand images in one folder (mine is ~8000) 2. Open that folder in the Files app (the grid loads fine and scrolls fine) 3. Click any image to open it in the viewer 4. Image opens, then the tab freezes ~20s and the slow script warning shows up **Expected behavior** The image opens and I can move through prev/next normally without the tab freezing, the same way it works in a normal sized folder. **Screenshots** Nothing useful, its just the standard Firefox "page is slowing down" dialog. I do have a performance profile though, see below. **Desktop (please complete the following information):** - OS: Windows 11 - Browser: Firefox - Version: 151 **Smartphone (please complete the following information):** - n/a, didnt test on mobile **Browser log** No real errors in the console, its a silent freeze and not a thrown exception. So instead of a log I grabbed a profile. Since theres no error log, heres what the Firefox profiler showed, which is the useful part. The freeze is entirely javascript on the main thread, about 21 seconds of it in one solid block. Stuff I ruled out: not the network (previews lazy load normally, no flood of requests), not the image (its a 420kb jpeg), and not rendering (no paint work in the hot path, it hangs before the carousel even draw). The hot stack lands in openFileInfo in src/views/Viewer.vue, around line 803 (its 794 on 33.x), where it builds this.fileList. It runs an Array .find() over the whole folder list, inside a .map() over that same list, so the work grows with the square of the number of files. The value it compares against (node.path) also looks like it parses a URL every time its read, because almost all the self time in the profile is URL parsing and encoding (SetSpecWithEncoding, CoalescePath, encodeURIComponent and friends). At 8000 files thats a huge number of url parses, which fits why a small folder is instant and this one isnt. Happy to attach the raw profile if you want it.