Sync fails without error - impossible to download or upload - tried everything

The Basics

  • Nextcloud Server version :
    • 32.0.3.2
  • Operating system and version (e.g., Ubuntu 24.04):
    • Docker container (Debian-based, from official nextcloud:latest image)
  • Web server and version (e.g, Apache 2.4.25):
    • Apache 2.4.65 (Debian)
  • Reverse proxy and version _(e.g. nginx 1.27.2)
    • Traefik
  • PHP version (e.g, 8.3):
    • 8.3.28
  • Is this the first time you’ve seen this error? (Yes / No):
    • Yes - sync was working before
  • When did this problem seem to first start?
    • After copying files directly into the local Nextcloud sync folder
  • Installation method (e.g. AlO, NCP, Bare Metal/Archive, etc.)
    • Docker Compose with official nextcloud:latest image
  • Are you using CloudfIare, mod_security, or similar? (Yes / No)
    • No

Summary of the issue you are facing:

Desktop sync client (4.0.4daily on CachyOS Linux) fails to transfer any data. Client detects tens of thousands of files to sync but UI shows “Synchronizing file 0 out of X” where X rapidly increases, then displays: “We could not process your request, please try synchronizing again later.” Server logs show only PROPFIND requests (directory listings), zero PUT/GET requests. No errors in Nextcloud logs. Web interface and mobile apps work fine.

Steps to replicate it:

Not sure how to replicate, I have 102GB of data on server and sync simply stopped working suddenty - now nothing sync, neither uploading nor downloading.

  • Changed sync folder location => same issue
  • Cleared client cache => no change
  • Ran occ files:scan user => completed successfully
  • Completely removed client config (rm -rf ~/.config/Nextcloud/ ~/.local/share/Nextcloud/)
  • Deleted account and reconfigured from scratch with fresh empty sync folder => same issue persists
  • Verified all server configs and limits

Log entries

Nextcloud

Only deprecation warnings (level 0), no actual errors during sync attempts:

{“reqId”:“GABU8dFdA21Aq8HA0UuV”,“level”:0,“time”:“2026-01-03T03:31:32+00:00”,“remoteAddr”:“...",“user”:“user”,“app”:“dav”,“method”:“PROPFIND”,“url”:“/remote.php/dav/files/user/”,“userAgent”:“Mozilla/5.0 (Linux) mirall/4.0.4daily (Nextcloud, cachyos-6.18.2-2-cachyos ClientArchitecture: x86_64 OsArchitecture: x86_64)”,“version”:“32.0.3.2”}

Web server / Reverse Proxy

Apache access logs show only PROPFIND requests, no PUT/GET for actual file transfers:

192.0.2.10 - user [03/Jan/2026:03:31:32 +0000] "PROPFIND /remote.php/dav/files/user/ HTTP/1.1" 207 234 "-" "Mozilla/5.0 (Linux) mirall/4.0.4daily (Nextcloud, cachyos-6.18.2-2-cachyos ClientArchitecture: x86_64 OsArchitecture: x86_64)"

No errors in Apache error.log related to sync.

Desktop Client Logs

#=#=#=# Syncrun finished 2026-01-03T04:10:06Z (last step: 136 msec, total: 849 msec)
#=#=#=# Syncrun started 2026-01-03T04:11:04Z
#=#=#=# Syncrun finished 2026-01-03T04:11:59Z (last step: 55710 msec, total: 55710 msec)
#=#=#=# Syncrun started 2026-01-03T04:12:11Z
#=#=#=# Syncrun finished 2026-01-03T04:13:08Z (last step: 57057 msec, total: 57057 msec)
#=#=#=# Syncrun started 2026-01-03T04:23:35Z
#=#=#=# Syncrun finished 2026-01-03T04:24:32Z (last step: 57580 msec, total: 57580 msec)

Configuration

Nextcloud

{
    "system": {
        "filelocking.enabled": true,
        "chunk_uploads": false,
        "htaccess.RewriteBase": "\/",
        "apps_paths": [
            {
                "path": "\/var\/www\/html\/apps",
                "url": "\/apps",
                "writable": false
            },
            {
                "path": "\/var\/www\/html\/custom_apps",
                "url": "\/custom_apps",
                "writable": true
            }
        ],
        "overwritehost": "cloud.mydomain.com",
        "overwriteprotocol": "https",
        "upgrade.disable-web": true,
        "instanceid": "***REMOVED SENSITIVE VALUE***",
        "passwordsalt": "***REMOVED SENSITIVE VALUE***",
        "secret": "***REMOVED SENSITIVE VALUE***",
        "trusted_domains": [
            "cloud.mydomain.com"
        ],
        "datadirectory": "***REMOVED SENSITIVE VALUE***",
        "dbtype": "mysql",
        "version": "32.0.3.2",
        "overwrite.cli.url": "https:\/\/cloud.mydomain.com",
        "dbname": "***REMOVED SENSITIVE VALUE***",
        "dbhost": "***REMOVED SENSITIVE VALUE***",
        "dbtableprefix": "oc_",
        "mysql.utf8mb4": true,
        "dbuser": "***REMOVED SENSITIVE VALUE***",
        "dbpassword": "***REMOVED SENSITIVE VALUE***",
        "installed": true,
        "trusted_proxies": "***REMOVED SENSITIVE VALUE***",
        "max_chunk_size": "10737418240",
        "forwarded_for_headers": [
            "HTTP_X_FORWARDED_FOR"
        ],
        "mail_domain": "***REMOVED SENSITIVE VALUE***",
        "mail_smtpmode": "smtp",
        "mail_sendmailmode": "smtp",
        "mail_from_address": "***REMOVED SENSITIVE VALUE***",
        "debug": false,
        "loglevel": 0,
        "maintenance": false,
        "memcache.local": "\\OC\\Memcache\\APCu",
        "mail_smtphost": "***REMOVED SENSITIVE VALUE***",
        "mail_smtpauth": true,
        "mail_smtpstreamoptions": {
            "ssl": {
                "allow_self_signed": true,
                "verify_peer": false,
                "verify_peer_name": false
            }
        },
        "mail_smtpname": "***REMOVED SENSITIVE VALUE***",
        "mail_smtppassword": "***REMOVED SENSITIVE VALUE***",
        "mail_smtpport": "465",
        "memcache.distributed": "\\OC\\Memcache\\Redis",
        "memcache.locking": "\\OC\\Memcache\\Redis",
        "redis": {
            "host": "***REMOVED SENSITIVE VALUE***",
            "password": "***REMOVED SENSITIVE VALUE***",
            "port": 6379
        },
        "htaccess.IgnoreFrontController": true,
        "mail_smtpsecure": "ssl",
        "maintenance_window_start": 6,
        "enabledPreviewProviders": [
            "OC\\Preview\\Movie",
            "OC\\Preview\\PNG",
            "OC\\Preview\\JPEG",
            "OC\\Preview\\GIF",
            "OC\\Preview\\BMP"
        ],
        "files.chunked_upload.max_size": 20971520,
        "data-fingerprint": "bbb361d6c9dbff2b86e0d7a215589c19"
    }
}

(Note: chunk_uploads was set to false - I reset it to true but the problem persists)

PHP Environment Variables (Docker)

PHP_MEMORY_LIMIT=4096M
PHP_UPLOAD_MAX_FILESIZE=10G
PHP_POST_MAX_SIZE=10G
PHP_MAX_EXECUTION_TIME=7200
PHP_MAX_INPUT_TIME=7200
APACHE_BODY_LIMIT=0

Apache MPM

ServerLimit              400
MaxRequestWorkers        400
MaxConnectionsPerChild   1000
Timeout                  3600
KeepAliveTimeout         300

Server

  • Quota: Unlimited
  • Disk space: 2.5TB available (27% usage)
  • MariaDB: max_allowed_packet=1G
  • Redis: 2GB maxmemory

Apps

Enabled:
  - activity: 5.0.0-dev.0
  - bruteforcesettings: 5.0.0-dev.0
  - calendar: 6.1.1
  - circles: 32.0.0
  - cloud_federation_api: 1.16.0
  - comments: 1.22.0
  - contacts: 8.1.1
  - contactsinteraction: 1.13.1
  - dashboard: 7.12.0
  - dav: 1.34.2
  - federatedfilesharing: 1.22.0
  - federation: 1.22.0
  - files: 2.4.0
  - files_downloadlimit: 5.0.0-dev.0
  - files_pdfviewer: 5.0.0-dev.0
  - files_reminders: 1.5.0
  - files_sharing: 1.24.1
  - files_trashbin: 1.22.0
  - files_versions: 1.25.0
  - firstrunwizard: 5.0.0-dev.0
  - logreader: 5.0.0-dev.0
  - lookup_server_connector: 1.20.0
  - nextcloud_announcements: 4.0.0-dev.0
  - notes: 4.12.4
  - notifications: 5.0.0-dev.0
  - oauth2: 1.20.0
  - password_policy: 4.0.0-dev.0
  - photos: 5.0.0-dev.1
  - privacy: 4.0.0-dev.0
  - profile: 1.1.0
  - provisioning_api: 1.22.0
  - recommendations: 5.0.0-dev.0
  - related_resources: 3.0.0-dev.0
  - richdocuments: 9.0.2
  - richdocumentscode: 25.4.702
  - serverinfo: 4.0.0-dev.0
  - settings: 1.15.1
  - sharebymail: 1.22.0
  - support: 4.0.0-dev.0
  - survey_client: 4.0.0-dev.0
  - systemtags: 1.22.0
  - text: 6.0.1
  - theming: 2.7.0
  - twofactor_backupcodes: 1.21.0
  - updatenotification: 1.22.0
  - user_status: 1.12.0
  - viewer: 5.0.0-dev.0
  - weather_status: 1.12.0
  - webhook_listeners: 1.3.0
  - workflowengine: 2.14.0
Disabled:
  - admin_audit: 1.22.0
  - app_api: 32.0.0 (installed 32.0.0)
  - encryption: 2.20.0
  - files_external: 1.24.0
  - spreed: 22.0.4 (installed 22.0.4)
1 Like

Does it happen only with the test (daily) build?

Tried daily, beta and stable from client version 4.0.4 also tried downgrading every version up to 3.17.3

Yes, same issue here. I have recently updated my nextcloud server to 32.0.3 and have a Linux client Nextcloud version 4.0.1-2 (Debian built) and have the same issue. In the small menu in the taskbar it tells me “Some files coulnd’t be synced“. When I open the full menu and click on “Nextcloud Settings“, it tells me “We couldn’t process your request. Please try syncing again later…”. Nothing else. I’m not sure what’s causing this.

I also use Traefik as reverse proxy. My setup looks very similar to yours.

If you’re using Traefik and recently updated in (in the past month or so), you may need to opt out of some changes they made regarding path encoding. See Traefik’s Issues/release notes/docs.

1 Like

Try to create one folder tree manually on the Nextcloud server. We’ve just discussed the same issue with the Linux Desktop client in an other thread these days.

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