General troubleshooting

If you have trouble installing, configuring or maintaining Nextcloud, please refer to our community support channels:

Please understand that all these channels essentially consist of users like you helping each other out. Consider helping others out where you can, to contribute back for the help you get. This is the only way to keep a community like Nextcloud healthy and sustainable!

If you are using Nextcloud in a business or otherwise large scale deployment, note that Nextcloud GmbH offers commercial support options.

Bugs

If you think you have found a bug in Nextcloud, please:

  • Search for a solution (see the options above)

  • Double-check your configuration

If you can’t find a solution, please use our bugtracker. You can generate a configuration report with the occ config command, with passwords automatically obscured.

General troubleshooting

Check the Nextcloud System requirements, especially supported browser versions.

When you see warnings about code integrity, refer to Code signing.

Disable 3rdparty / non-shipped apps

It might be possible that 3rd party / non-shipped apps are causing various different issues. Always disable 3rd party apps before upgrades, and for troubleshooting. Please refer to the Apps commands on how to disable an app from command line.

Nextcloud logfiles

In a standard Nextcloud installation the log level is set to Normal. To find any issues you need to raise the log level to All in your config.php file, or to Everything on your Nextcloud Admin page. Please see Logging for more information on these log levels.

Some logging - for example JavaScript console logging - needs debugging enabled. Edit config/config.php and change 'debug' => false, to 'debug' => true, Be sure to change it back when you are finished.

For JavaScript issues you will also need to view the javascript console. All major browsers have developer tools for viewing the console, and you usually access them by pressing F12.

Note

The logfile of Nextcloud is located in the data directory nextcloud/data/nextcloud.log.

PHP version and information

You will need to know your PHP version and configurations. To do this, create a plain-text file named phpinfo.php and place it in your Web root, for example /var/www/html/phpinfo.php. (Your Web root may be in a different location; your Linux distribution documentation will tell you where.) This file contains just this line:

<?php phpinfo(); ?>

Open this file in a Web browser by pointing your browser to localhost/phpinfo.php:

../_images/phpinfo.png

Your PHP version is at the top, and the rest of the page contains abundant system information such as active modules, active .ini files, and much more. When you are finished reviewing your information you must delete phpinfo.php, or move it outside of your Web directory, because it is a security risk to expose such sensitive data.

Debugging sync issues

Warning

The data directory on the server is exclusive to Nextcloud and must not be modified manually.

Disregarding this can lead to unwanted behaviors like:

  • Problems with sync clients

  • Undetected changes due to caching in the database

If you need to directly upload files from the same server please use a WebDAV command line client like cadaver to upload files to the WebDAV interface at:

https://example.com/nextcloud/remote.php/dav

Common problems / error messages

Some common problems / error messages found in your logfiles as described above:

  • SQLSTATE[HY000] [1040] Too many connections -> You need to increase the connection limit of your database, please refer to the manual of your database for more information.

  • SQLSTATE[HY000]: General error: 5 database is locked -> You’re using SQLite which can’t handle a lot of parallel requests. Please consider converting to another database like described in Converting database type.

  • SQLSTATE[HY000]: General error: 2006 MySQL server has gone away -> Please refer to Troubleshooting for more information.

  • SQLSTATE[HY000] [2002] No such file or directory -> There is a problem accessing your SQLite database file in your data directory (data/nextcloud.db). Please check the permissions of this folder/file or if it exists at all. If you’re using MySQL please start your database.

  • Connection closed / Operation cancelled -> This could be caused by wrong KeepAlive settings within your Apache config. Make sure that KeepAlive is set to On and also try to raise the limits of KeepAliveTimeout and MaxKeepAliveRequests.

  • No basic authentication headers were found -> This error is shown in your data/nextcloud.log file. Some Apache modules like mod_fastcgi, mod_fcgid or mod_proxy_fcgi are not passing the needed authentication headers to PHP and so the login to Nextcloud via WebDAV, CalDAV and CardDAV clients is failing.

Troubleshooting Web server and PHP problems

Logfiles

When having issues the first step is to check the logfiles provided by PHP, the Web server and Nextcloud itself.

Note

In the following the paths to the logfiles of a default Debian installation running Apache2 with mod_php is assumed. On other Web servers, Linux distros or operating systems they can differ.

  • The logfile of Apache2 is located in /var/log/apache2/error.log.

  • The logfile of PHP can be configured in your /etc/php/8.0/apache2/php.ini. You need to set the directive log_errors to On and choose the path to store the logfile in the error_log directive. After those changes you need to restart your Web server.

  • The logfile of Nextcloud is located in the data directory /var/www/nextcloud/data/nextcloud.log.

Web server and PHP modules

Note

Lighttpd is not supported with Nextcloud, and some Nextcloud features may not work at all on Lighttpd.

There are some Web server or PHP modules which are known to cause various problems like broken uploads/downloads. The following shows a draft overview of these modules:

  1. Apache

  • mod_pagespeed

  • mod_evasive

  • mod_security

  • mod_reqtimeout

  • mod_deflate

  • libapache2-mod-php*filter (use libapache2-mod-php8.0 instead)

  • mod_spdy together with libapache2-mod-php5 / mod_php (use fcgi or php-fpm instead)

  • mod_dav

  • mod_xsendfile / X-Sendfile (causing broken downloads if not configured correctly)

  1. NginX

  • ngx_pagespeed

  • HttpDavModule

  • X-Sendfile (causing broken downloads if not configured correctly)

  1. PHP

  • eAccelerator

Troubleshooting WebDAV

Nextcloud uses SabreDAV, and the SabreDAV documentation is comprehensive and helpful.

See:

There is also a well maintained FAQ thread available at the ownCloud Forums which contains various additional information about WebDAV problems.

Service discovery

Some clients - especially on iOS/macOS - have problems finding the proper sync URL, even when explicitly configured to use it.

If you want to use CalDAV or CardDAV clients or other clients that require service discovery together with Nextcloud it is important to have a correct working setup of the following URLs:

https://example.com/.well-known/carddav
https://example.com/.well-known/caldav

Those need to be redirecting your clients to the correct endpoints. If Nextcloud is running at the document root of your Web server the correct URL is https://example.com/remote.php/dav for CardDAV and CalDAV and if running in a subfolder like nextcloud, then https://example.com/nextcloud/remote.php/dav.

For the first case the .htaccess file shipped with Nextcloud should do this work for you when you’re running Apache. You need to make sure that your Web server is using this file. Additionally, you need the mod_rewrite Apache module installed to process these redirects. When running Nginx please refer to NGINX configuration.

If your Nextcloud instance is installed in a subfolder called nextcloud and you’re running Apache, create or edit the .htaccess file within the document root of your Web server and add the following lines:

<IfModule mod_rewrite.c>
  RewriteEngine on
  RewriteRule ^\.well-known/carddav /nextcloud/remote.php/dav [R=301,L]
  RewriteRule ^\.well-known/caldav /nextcloud/remote.php/dav [R=301,L]
  RewriteRule ^\.well-known/webfinger /nextcloud/index.php/.well-known/webfinger [R=301,L]
  RewriteRule ^\.well-known/nodeinfo /nextcloud/index.php/.well-known/nodeinfo [R=301,L]
</IfModule>

Make sure to change /nextcloud to the actual subfolder your Nextcloud instance is running in.

Note

If you put the above directives directly into an Apache configuration file (usually within /etc/apache2/) instead of .htaccess, you need to prepend the first argument of each RewriteRule option with a forward slash /, for example ^/\.well-known/carddav. This is because Apache normalizes paths for the use in .htaccess files by dropping any number of leading slashes, but it does not do so for the use in its main configuration files.

If you are running NGINX, make sure location = /.well-known/carddav { and location = /.well-known/caldav { are properly configured as described in NGINX configuration, adapt to use a subfolder if necessary.

Now change the URL in the client settings to just use:

https://example.com

instead of e.g.

https://example.com/nextcloud/remote.php/dav/principals/username.

There are also several techniques to remedy this, which are described extensively at the Sabre DAV website.

Troubleshooting sharing

Users’ Federated Cloud IDs not updated after a domain name change

  1. run Database query

DELETE FROM oc_cards_properties WHERE name = 'CLOUD' AND addressbookid = (select id from oc_addressbooks where principaluri = 'principals/system/system' AND uri = 'system');

  1. run occ commands

occ dav:sync-system-addressbook
occ federation:sync-addressbooks

Troubleshooting file encoding on external storages

When using external storage, it can happen that some files with special characters will not appear in the file listing, or they will appear and not be accessible.

When this happens, please run the files scanner, for example with:

sudo -u www-data php occ files:scan --all

If the scanner tells about an encoding issue on the affected file, please enable Mac encoding compatibility in the mount options and then rescan the external storage.

Note

This mode comes with a performance impact because Nextcloud will always try both encodings when detecting files on external storages.

Mac computers are using the NFD Unicode Normalization for file names which is different than NFC, the one used by other operating systems. Mac users might upload files directly to the external storage using NFD normalized file names. When uploading through Nextcloud, file names will always be normalized to the NFC standard for consistency.

It is recommended to let Nextcloud use external storages exclusively to avoid such issues.

See also technical explanation about NFC vs NFD normalizations.

Troubleshooting contacts & calendar

Unable to update contacts or events

If you get an error like:

PATCH https://example.com/remote.php/dav HTTP/1.0 501 Not Implemented

it is likely caused by one of the following reasons:

Using Pound reverse-proxy/load balancer

As of writing this Pound doesn’t support the HTTP/1.1 verb. Pound is easily patched to support HTTP/1.1.

Misconfigured Web server

Your Web server is misconfigured and blocks the needed DAV methods. Please refer to Troubleshooting WebDAV above for troubleshooting steps.

Troubleshooting data-directory

If you have a fresh install, consider reinstalling with your preferred directory location.

Unofficially moving the data directory can be done as follows:

  1. Make sure no cron jobs are running

  2. Stop apache

  3. Move /data to the new location

  4. Change the config.php entry

  5. Edit the database: In oc_storages change the path on the local::/old-data-dir/ entry

  6. Ensure permissions are still correct

  7. Restart apache

Warning

However this is not supported and you risk breaking your database.

For a safe moving of data directory, supported by Nextcloud, recommended actions are:

  1. Make sure no cron jobs are running

  2. Stop apache

  3. Move /data to the new location

  4. Create a symlink from the original location to the new location

  5. Ensure permissions are still correct

  6. Restart apache

Warning

Note, you may need to configure your webserver to support symlinks.

Troubleshooting quota or size issues

Sometimes it can happen that the used space reported in the web UI or with occ user:info $userId does not match the actual data stored in the user’s data/$userId/files directory.

Note

Metadata, versions, trashbin and encryption keys are not counted in the used space above. Please refer to the quota documentation for details.

Running the following command can help fix the sizes and quota for a given user:

sudo -u www-data php occ files:scan -vvv <user-id>

If encryption was enabled earlier on the instance and disabled later on, it is likely that some size values in the database did not correctly get reset upon decrypting. You can run the following SQL query to reset those after backing up the database:

UPDATE oc_filecache SET unencrypted_size=0 WHERE encrypted=0;

Troubleshooting downloading or decrypting files

Bad signature error

In some rare cases it can happen that encrypted files cannot be downloaded and return a “500 Internal Server Error”. If the Nextcloud log contains an error about “Bad Signature”, then the following command can be used to repair affected files:

occ encryption:fix-encrypted-version userId --path=/path/to/broken/file.txt

Replace “userId” and the path accordingly. The command will do a test decryption for all files and automatically repair the ones with a signature error.

Encryption key cannot be found

If the logs contain an error stating that the encryption key cannot be found, you can manually search the data directory for a folder that has the same name as the file name. For example if a file “example.md” cannot be decrypted, run:

find path/to/datadir -name example.md -type d

Then check the results located in the files_encryption folder. If the key folder is in the wrong location, you can move it to the correct folder and try again.

The data/files_encryption folder contains encryption keys for group folders and system-wide external storages while data/$userid/files_encryption contains the keys for specific user storage files.

Note

This can happen if encryption was disabled at some point but the occ command for decrypt-all was not run, and then someone moved the files to another location. Since encryption was disabled, the keys did not get moved.

Encryption key cannot be found with external storage or group folders

To resolve this issue, please run the following command:

sudo -u www-data php occ encryption:fix-key-location <user-id>

This will attempt to recover keys that were not moved properly.

If this doesn’t resolve the problem, please refer to the section Encryption key cannot be found for a manual procedure.

Note

There were two known issues where:

Fair Use Policy

Nextcloud is open source and you can host it for free on your own server or at a provider.

Nextcloud recommends Using Nextcloud Enterprise for deploying instances with more than 500 users. With that size, issues like a broken server or a data leak become very serious.

If there is an issue with the server, 500 people can’t work. A data leak would risk the data of many users. In short, the server should be considered mission-critical. We believe you and your users would have a better experience with Nextcloud Enterprise.

Nextcloud Enterprise is pre-configured and optimised for the needs of professional organisations rather than home users. It comes with support, security and scaling benefits, compliance expertise, and access to our knowledge about running a successful Nextcloud, to get the best possible experience for users and admins. This also reduces the load on our home user forum http://help.nextcloud.com from issues unique to big deployments.

Nextcloud provides some infrastructure components needed for Nextcloud servers to run reliably. This includes notification, our app store and more. To ensure these resources do not get overloaded by administrators who run Nextcloud for thousands of users without providing financial resources to Nextcloud in return, these components are limited and will not work for more than 500 users.

We believe all organisations who run Nextcloud for hundreds of users should be officially supported. We know there can be financial restrictions for non-profit organisations and, as we want everybody to have a chance to get the most out of Nextcloud, we have special offers for NGOs, small schools and other non-profits. Please reach out to talk to us about what is possible through the contact form on our site or ask your system administrator to reach out.

Other issues

Some services like Cloudflare can cause issues by minimizing JavaScript and loading it only when needed. When having issues like a not working login button or creating new users make sure to disable such services first.