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# General Troubleshooting

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

- The Nextcloud Forums

    The Nextcloud forums have a FAQ page where each topic corresponds to typical mistakes or frequently occurring issues

- The Nextcloud forums

- The Nextcloud IRC chat channel `irc://#nextcloud@freenode.net` on freenode.net, also accessible via webchat

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 Configuration 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. For Firefox we recommend to installing the Firebug extension.

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`:

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 behaviours 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. Information on how to correctly configure your environment can be found at the forums.

## 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/php5/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 up-/downloads. The following shows a draft overview of these modules:

1. Apache

- mod_pagespeed
- mod_evasive
- mod_security
- mod_reqtimeout
- mod_deflate
- libapache2-mod-php5filter (use libapache2-mod-php5 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)

2. NginX

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

3. PHP

- eAccelerator

## Troubleshooting WebDAV

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

See:

- SabreDAV FAQ
- Web servers (Lists lighttpd as not recommended)
- Working with large files (Shows a PHP bug in older SabreDAV versions and information for mod_security problems)
- 0 byte files (Reasons for empty files on the server)
- Clients (A comprehensive list of WebDAV clients, and possible problems with each one)
- Finder, OS X’s built-in WebDAV client (Describes problems with Finder on various Web servers)

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

## Troubleshooting Contacts & Calendar

### Service discovery

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

If you want to use CalDAV or CardDAV clients 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 DAV endpoints. If running Nextcloud at the document root of your Web server the correct URL is:

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

and if running in a subfolder like `nextcloud`:

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

For the first case the `.htaccess` file shipped with Nextcloud should do this work for your when running Apache. You only need to make sure that your Web server is using this file. When running Nginx please refer to :doc:`../installation/nginx.

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:

    Redirect 301 /.well-known/carddav /nextcloud/remote.php/dav
    Redirect 301 /.well-known/caldav /nextcloud/remote.php/dav

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.

### 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.

## 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.

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