Errors after upgrading to version Nextcloud 33 "Hub 26 Winter"

imak · February 19, 2026, 7:10am

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Some or all of the below information will be requested if it isn’t supplied; for fastest response please provide as much as you can.

The Basics

Nextcloud Server version (e.g., 29.x.x):
- 33.0.0
Operating system and version (e.g., Ubuntu 24.04):
- debian 12.13
Web server and version (e.g, Apache 2.4.25):
- Apache 2.4.66
Reverse proxy and version _(e.g. nginx 1.27.2)
- No
PHP version (e.g, 8.3):
- 8.3
Is this the first time you’ve seen this error? (Yes / No):
- Yes
When did this problem seem to first start?
- After update
Installation method (e.g. AlO, NCP, Bare Metal/Archive, etc.)
- Bare metal
Are you using CloudfIare, mod_security, or similar? (Yes / No)
- No

Summary of the issue you are facing:

[The content is not displayed in the “Files”, and the errors appear in the logs]

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

Upgrade to Nextclod 33 from the previous version

Log entries

Nextcloud

Please provide the log entries from your Nextcloud log that are generated during the time of problem (via the Copy raw option from Administration settings->Logging screen or from your nextcloud.log located in your data directory). Feel free to use a pastebin/gist service if necessary.

{"reqId":"ARTjVsAGGA44wF4sM5E6","level":3,"time":"2026-02-19T09:20:44+03:00","remoteAddr":"213.87.144.230","user":"user","app":"no app in context","method":"PROPFIND","url":"/remote.php/dav/files/user/%D0%93%D1%80%D1%83%D0%BF%D0%BF%D0%B0%20-%20%D0%9E%D1%81%D0%B5%D0%BD%D1%8C-2024.xlsx","scriptName":"/remote.php","message":"Uncaught exception","userAgent":"Mozilla/5.0 (Android) Nextcloud-android/3.34.1","version":"33.0.0.16","exception":{"Exception":"Error","Message":"Class \"OC\\Preview\\Provider\" not found","Code":0,"Trace":[{"file":"/var/www/nextcloud/lib/composer/composer/ClassLoader.php","line":576,"function":"include"},{"file":"/var/www/nextcloud/lib/composer/composer/ClassLoader.php","line":427,"function":"Composer\\Autoload\\{closure}","args":["*** sensitive parameters replaced ***"]},{"file":"/var/www/nextcloud/apps/officeonline/lib/Preview/OOXML.php","line":10,"function":"loadClass","class":"Composer\\Autoload\\ClassLoader","type":"->"},{"file":"/var/www/nextcloud/lib/composer/composer/ClassLoader.php","line":576,"args":["/var/www/nextcloud/apps/officeonline/lib/Preview/OOXML.php"],"function":"include"},{"file":"/var/www/nextcloud/lib/composer/composer/ClassLoader.php","line":427,"function":"Composer\\Autoload\\{closure}","args":["*** sensitive parameters replaced ***"]},{"function":"loadClass","class":"Composer\\Autoload\\ClassLoader","type":"->"},{"file":"/var/www/nextcloud/lib/private/AppFramework/Utility/SimpleContainer.php","line":129,"function":"__construct","class":"ReflectionClass","type":"->"},{"file":"/var/www/nextcloud/lib/private/AppFramework/Utility/SimpleContainer.php","line":157,"function":"resolve","class":"OC\\AppFramework\\Utility\\SimpleContainer","type":"->"},{"file":"/var/www/nextcloud/lib/private/AppFramework/DependencyInjection/DIContainer.php","line":360,"function":"query","class":"OC\\AppFramework\\Utility\\SimpleContainer","type":"->"},{"file":"/var/www/nextcloud/lib/private/AppFramework/DependencyInjection/DIContainer.php","line":330,"function":"queryNoFallback","class":"OC\\AppFramework\\DependencyInjection\\DIContainer","type":"->"},{"file":"/var/www/nextcloud/apps/officeonline/lib/AppInfo/Application.php","line":96,"function":"query","class":"OC\\AppFramework\\DependencyInjection\\DIContainer","type":"->"},{"file":"/var/www/nextcloud/lib/private/Preview/GeneratorHelper.php","line":38,"function":"OCA\\Officeonline\\AppInfo\\{closure}","class":"OCA\\Officeonline\\AppInfo\\Application","type":"->","args":["*** sensitive parameters replaced ***"]},{"file":"/var/www/nextcloud/lib/private/PreviewManager.php","line":230,"function":"getProvider","class":"OC\\Preview\\GeneratorHelper","type":"->"},{"file":"/var/www/nextcloud/apps/dav/lib/Connector/Sabre/FilesPlugin.php","line":398,"function":"isAvailable","class":"OC\\PreviewManager","type":"->"},{"file":"/var/www/nextcloud/3rdparty/sabre/dav/lib/DAV/PropFind.php","line":95,"function":"OCA\\DAV\\Connector\\Sabre\\{closure}","class":"OCA\\DAV\\Connector\\Sabre\\FilesPlugin","type":"->","args":["*** sensitive parameters replaced ***"]},{"file":"/var/www/nextcloud/apps/dav/lib/Connector/Sabre/FilesPlugin.php","line":397,"function":"handle","class":"Sabre\\DAV\\PropFind","type":"->"},{"file":"/var/www/nextcloud/3rdparty/sabre/event/lib/WildcardEmitterTrait.php","line":89,"function":"handleGetProperties","class":"OCA\\DAV\\Connector\\Sabre\\FilesPlugin","type":"->"},{"file":"/var/www/nextcloud/3rdparty/sabre/dav/lib/DAV/Server.php","line":1052,"function":"emit","class":"Sabre\\DAV\\Server","type":"->"},{"file":"/var/www/nextcloud/3rdparty/sabre/dav/lib/DAV/Server.php","line":984,"function":"getPropertiesByNode","class":"Sabre\\DAV\\Server","type":"->"},{"file":"/var/www/nextcloud/3rdparty/sabre/dav/lib/DAV/Server.php","line":1664,"function":"getPropertiesIteratorForPath","class":"Sabre\\DAV\\Server","type":"->"},{"file":"/var/www/nextcloud/3rdparty/sabre/dav/lib/DAV/Server.php","line":1649,"function":"writeMultiStatus","class":"Sabre\\DAV\\Server","type":"->"},{"file":"/var/www/nextcloud/3rdparty/sabre/dav/lib/DAV/CorePlugin.php","line":346,"function":"generateMultiStatus","class":"Sabre\\DAV\\Server","type":"->"},{"file":"/var/www/nextcloud/3rdparty/sabre/event/lib/WildcardEmitterTrait.php","line":89,"function":"httpPropFind","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/apps/dav/lib/Connector/Sabre/Server.php","line":212,"function":"invokeMethod","class":"Sabre\\DAV\\Server","type":"->"},{"file":"/var/www/nextcloud/apps/dav/lib/Server.php","line":427,"function":"start","class":"OCA\\DAV\\Connector\\Sabre\\Server","type":"->"},{"file":"/var/www/nextcloud/apps/dav/appinfo/v2/remote.php","line":25,"function":"exec","class":"OCA\\DAV\\Server","type":"->"},{"file":"/var/www/nextcloud/remote.php","line":151,"args":["/var/www/nextcloud/apps/dav/appinfo/v2/remote.php"],"function":"require_once"}],"File":"/var/www/nextcloud/apps/officeonline/lib/Preview/Office.php","Line":17,"message":"Uncaught exception","exception":"{\"class\":\"Error\",\"message\":\"Class \\\"OC\\Preview\\Provider\\\" not found\",\"code\":0,\"file\":\"/var/www/nextcloud/apps/officeonline/lib/Preview/Office.php:17\",\"trace\":\"#0 /var/www/nextcloud/lib/composer/composer/ClassLoader.php(576): include()\\n#1 /var/www/nextcloud/lib/composer/composer/ClassLoader.php(427): Composer\\Autoload\\{closure}()\\n#2 /var/www/nextcloud/apps/officeonline/lib/Preview/OOXML.php(10): Composer\\Autoload\\ClassLoader->loadClass()\\n#3 /var/www/nextcloud/lib/composer/composer/ClassLoader.php(576): include('...')\\n#4 /var/www/nextcloud/lib/composer/composer/ClassLoader.php(427): Composer\\Autoload\\{closure}()\\n#5 [internal function]: Composer\\Autoload\\ClassLoader->loadClass()\\n#6 /var/www/nextcloud/lib/private/AppFramework/Utility/SimpleContainer.php(129): ReflectionClass->__construct()\\n#7 /var/www/nextcloud/lib/private/AppFramework/Utility/SimpleContainer.php(157): OC\\AppFramework\\Utility\\SimpleContainer->resolve()\\n#8 /var/www/nextcloud/lib/private/AppFramework/DependencyInjection/DIContainer.php(360): OC\\AppFramework\\Utility\\SimpleContainer->query()\\n#9 /var/www/nextcloud/lib/private/AppFramework/DependencyInjection/DIContainer.php(330): OC\\AppFramework\\DependencyInjection\\DIContainer->queryNoFallback()\\n#10 /var/www/nextcloud/apps/officeonline/lib/AppInfo/Application.php(96): OC\\AppFramework\\DependencyInjection\\DIContainer->query()\\n#11 /var/www/nextcloud/lib/private/Preview/GeneratorHelper.php(38): OCA\\Officeonline\\AppInfo\\Application->OCA\\Officeonline\\AppInfo\\{closure}()\\n#12 /var/www/nextcloud/lib/private/PreviewManager.php(230): OC\\Preview\\GeneratorHelper->getProvider()\\n#13 /var/www/nextcloud/apps/dav/lib/Connector/Sabre/FilesPlugin.php(398): OC\\PreviewManager->isAvailable()\\n#14 /var/www/nextcloud/3rdparty/sabre/dav/lib/DAV/PropFind.php(95): OCA\\DAV\\Connector\\Sabre\\FilesPlugin->OCA\\DAV\\Connector\\Sabre\\{closure}()\\n#15 /var/www/nextcloud/apps/dav/lib/Connector/Sabre/FilesPlugin.php(397): Sabre\\DAV\\PropFind->handle()\\n#16 /var/www/nextcloud/3rdparty/sabre/event/lib/WildcardEmitterTrait.php(89): OCA\\DAV\\Connector\\Sabre\\FilesPlugin->handleGetProperties()\\n#17 /var/www/nextcloud/3rdparty/sabre/dav/lib/DAV/Server.php(1052): Sabre\\DAV\\Server->emit()\\n#18 /var/www/nextcloud/3rdparty/sabre/dav/lib/DAV/Server.php(984): Sabre\\DAV\\Server->getPropertiesByNode()\\n#19 /var/www/nextcloud/3rdparty/sabre/dav/lib/DAV/Server.php(1664): Sabre\\DAV\\Server->getPropertiesIteratorForPath()\\n#20 /var/www/nextcloud/3rdparty/sabre/dav/lib/DAV/Server.php(1649): Sabre\\DAV\\Server->writeMultiStatus()\\n#21 /var/www/nextcloud/3rdparty/sabre/dav/lib/DAV/CorePlugin.php(346): Sabre\\DAV\\Server->generateMultiStatus()\\n#22 /var/www/nextcloud/3rdparty/sabre/event/lib/WildcardEmitterTrait.php(89): Sabre\\DAV\\CorePlugin->httpPropFind()\\n#23 /var/www/nextcloud/3rdparty/sabre/dav/lib/DAV/Server.php(472): Sabre\\DAV\\Server->emit()\\n#24 /var/www/nextcloud/apps/dav/lib/Connector/Sabre/Server.php(212): Sabre\\DAV\\Server->invokeMethod()\\n#25 /var/www/nextcloud/apps/dav/lib/Server.php(427): OCA\\DAV\\Connector\\Sabre\\Server->start()\\n#26 /var/www/nextcloud/apps/dav/appinfo/v2/remote.php(25): OCA\\DAV\\Server->exec()\\n#27 /var/www/nextcloud/remote.php(151): require_once('...')\\n#28 {main}\"}","CustomMessage":"Uncaught exception"},"id":"6996b0277ef05"}

Web Browser

If the problem is related to the Web interface, open your browser inspector Console and Network tabs while refreshing (reloading) and reproducing the problem. Provide any relevant output/errors here that appear.

PASTE

Web server / Reverse Proxy

The output of your Apache/nginx/system log in /var/log/____:

PASTE HERE

Configuration

Nextcloud

The output of occ config:list system or similar is best, but, if not possible, the contents of your config.php file from /path/to/nextcloud is fine (make sure to remove any identifiable information!):

{
    "system": {
        "instanceid": "***REMOVED SENSITIVE VALUE***",
        "passwordsalt": "***REMOVED SENSITIVE VALUE***",
        "secret": "***REMOVED SENSITIVE VALUE***",
        "trusted_domains": [
            "ibis.newacropol.ru"
        ],
        "datadirectory": "***REMOVED SENSITIVE VALUE***",
        "dbtype": "mysql",
        "version": "33.0.0.16",
        "overwrite.cli.url": "https:\/\/ibis.newacropol.ru",
        "overwriteprotocol": "https",
        "dbname": "***REMOVED SENSITIVE VALUE***",
        "dbhost": "***REMOVED SENSITIVE VALUE***",
        "dbport": "",
        "dbtableprefix": "oc_",
        "mysql.utf8mb4": true,
        "dbuser": "***REMOVED SENSITIVE VALUE***",
        "dbpassword": "***REMOVED SENSITIVE VALUE***",
        "installed": true,
        "logtimezone": "Europe\/Moscow",
        "logdateformat": "Y-m-d_H:i:s",
        "log_type": "file",
        "logfile": "\/var\/log\/nextcloud\/nextcloud.log",
        "loglevel": 2,
        "log_rotate_size": 104857600,
        "memcache.locking": "\\OC\\Memcache\\Redis",
        "memcache.local": "\\OC\\Memcache\\Redis",
        "redis": {
            "host": "***REMOVED SENSITIVE VALUE***",
            "port": 6379
        },
        "default_phone_region": "RU",
        "maintenance_window_start": 1,
        "maintenance": false,
        "lost_password_link": false,
        "ldapProviderFactory": "OCA\\User_LDAP\\LDAPProviderFactory",
        "mail_smtpmode": "smtp",
        "mail_smtpsecure": "tls",
        "mail_sendmailmode": "smtp",
        "mail_from_address": "***REMOVED SENSITIVE VALUE***",
        "mail_domain": "***REMOVED SENSITIVE VALUE***",
        "mail_smtpauthtype": "PLAIN",
        "mail_smtpauth": 1,
        "mail_smtphost": "***REMOVED SENSITIVE VALUE***",
        "mail_smtpport": "587",
        "mail_smtpname": "***REMOVED SENSITIVE VALUE***",
        "mail_smtppassword": "***REMOVED SENSITIVE VALUE***",
        "theme": "",
        "memories.db.triggers.fcu": true,
        "memories.exiftool": "\/var\/www\/nextcloud\/apps\/memories\/bin-ext\/exiftool-amd64-glibc",
        "memories.vod.path": "\/var\/www\/nextcloud\/apps\/memories\/bin-ext\/go-vod-amd64",
        "forbidden_filename_basenames": [
            "con",
            "prn",
            "aux",
            "nul",
            "com0",
            "com1",
            "com2",
            "com3",
            "com4",
            "com5",
            "com6",
            "com7",
            "com8",
            "com9",
            "com\u00b9",
            "com\u00b2",
            "com\u00b3",
            "lpt0",
            "lpt1",
            "lpt2",
            "lpt3",
            "lpt4",
            "lpt5",
            "lpt6",
            "lpt7",
            "lpt8",
            "lpt9",
            "lpt\u00b9",
            "lpt\u00b2",
            "lpt\u00b3"
        ],
        "forbidden_filename_characters": [
            "<",
            ">",
            ":",
            "\"",
            "|",
            "?",
            "*",
            "\\",
            "\/"
        ],
        "forbidden_filename_extensions": [
            " ",
            ".",
            ".filepart",
            ".part"
        ],
        "memories.vod.ffmpeg": "\/usr\/bin\/ffmpeg",
        "memories.vod.ffprobe": "\/usr\/bin\/ffprobe",
        "app_install_overwrite": [],
        "updater.secret": "***REMOVED SENSITIVE VALUE***"
    }
}

Apps

The output of occ app:list (if possible).

Enabled:

activity: 6.0.0-dev.0
bruteforcesettings: 6.0.0-dev.0
calendar: 6.2.0
circles: 33.0.0
cloud_federation_api: 1.17.0
comments: 1.23.0
contacts: 8.3.3
contactsinteraction: 1.14.1
dav: 1.36.0
deck: 1.17.0
epubviewer: 1.9.2
federatedfilesharing: 1.23.0
files: 2.5.0
files_downloadlimit: 5.1.0-dev.0
files_external: 1.25.1
files_pdfviewer: 6.0.0-dev.0
files_reminders: 1.6.0
files_sharing: 1.25.2
files_trashbin: 1.23.0
files_versions: 1.26.0
groupfolders: 21.0.4
logcleaner: 1.3.1
logreader: 6.0.0
lookup_server_connector: 1.21.0
nextcloud_announcements: 5.0.0
notes: 4.13.0
notifications: 6.0.0
oauth2: 1.21.0
officeonline: 3.1.1
password_policy: 5.0.0-dev.0
photos: 6.0.0-dev.0
privacy: 5.0.0-dev.0
profile: 1.2.0
provisioning_api: 1.23.0
related_resources: 4.0.0-dev.0
serverinfo: 5.0.0-dev.0
settings: 1.16.0
sharebymail: 1.23.0
systemtags: 1.23.0
tasks: 0.17.1
text: 7.0.0-dev.3
theming: 2.8.0
twofactor_backupcodes: 1.22.0
twofactor_totp: 15.0.0-dev.0
updatenotification: 1.23.0
user_ldap: 1.24.0
viewer: 6.0.0-dev.0
webhook_listeners: 1.5.0
workflowengine: 2.15.0
Disabled:
admin_audit: 1.23.0
app_api: 33.0.0 (installed 32.0.0)
audioplayer: 3.7.0 (installed 3.7.0)
dashboard: 7.13.0 (installed 7.1.0)
encryption: 2.21.0
federation: 1.23.0 (installed 1.14.0)
firstrunwizard: 6.0.0-dev.0 (installed 2.13.0)
memories: 7.8.2 (installed 7.8.2)
music: 2.5.1 (installed 2.5.1)
quicknotes: 0.8.40 (installed 0.8.40)
recommendations: 6.0.0-dev.0 (installed 1.3.0)
support: 5.0.0 (installed 1.5.0)
survey_client: 5.0.0-dev.0 (installed 1.10.0)
suspicious_login: 11.0.0-dev.0
twofactor_nextcloud_notification: 7.0.0
user_status: 1.13.0 (installed 1.4.0)
weather_status: 1.13.0 (installed 1.0.0)
workflow_media_converter: 2.0.0 (installed 2.0.0)

Tips for increasing the likelihood of a response

Use the preformatted text formatting option in the editor for all log entries and configuration output.
If screenshots are useful, feel free to include them.
- If possible, also include key error output in text form so it can be searched for.
Try to edit log output only minimally (if at all) so that it can be ran through analyzers / formatters by those trying to help you.

wwe · February 19, 2026, 9:21am

most relevant details IMO

	"url": "/remote.php/dav/files/user/%D0%93%D1%80%D1%83%D0%BF%D0%BF%D0%B0%20-%20%D0%9E%D1%81%D0%B5%D0%BD%D1%8C-2024.xlsx",

	"message": "Uncaught exception",
	"userAgent": "Mozilla/5.0 (Android) Nextcloud-android/3.34.1",

	"version": "33.0.0.16",

	"exception": {
		"Exception": "Error",
		"Message": "Class \"OC\\Preview\\Provider\" not found",

Pleas explain further if the the problem

is related to a specific xlsx file or occurs for all content
exception complains about preview - can you still access the file (download and edit?)
limited to mobile or happens on desktop and different browsers

do you have any office installed?

is is m365 Office integration?

I don’t see any preview config (enabledPreviewProviders: ) do you have it in your config.php?

imak · February 19, 2026, 3:09pm

Thank you for your reply

1. After updating, there is a problem with all file / folder content. When entering the “Files” section, the file structure cannot be displayed. Endless loading occurs. Checked in: Firefox, Opera, Chrome from Debian13, Windows 10, and Android.

The contents of “Notes,” “Calendar,” “Tasks,” and “Contacts” is displayed correctly.

2. Everything works fine on both desktop computers and smartphones via the synchronization client. The problem is only in the web interface.

3. As I wrote above, the problem occurs on all devices available to me.

wwe · February 19, 2026, 8:46pm

as preview is the only problem we see so far try to disable previews using
enable-previews - either change config.php and restart or set using occ

# check
occ config:app:set enable-previews
# disable
occ config:app:set enable-previews --value="false"

imak · February 19, 2026, 9:49pm

Thanks for the help.

Your advice helped restore the display of files.
Then I found the culprit of the problem. It was “officeonline”.

You noticed it in a previous post. It was installed to integrate with Collabora Office. The native extension “Nextcloude Office” on the previous version worked for me unstable.

Thanks again.

The problem is solved.