When loading DokuWiki, I'm getting an Error 500 (Internal Server Error), what should I do?

This can happen if the .htaccess files in your DokuWiki directory use settings or trigger actions which are not supported by your Apache server config. If you're not running the server yourself, but are registered with a webhost, you can either ask your webhost to enable the options in question, or just comment them out in the htaccess files.

The options which are known to cause an Error 500 are:

Options -Indexes

as well as all settings related to Apache's mod_rewrite option to pretty-print URLs. The latter are disabled by default.

It may also occur when setting very permissive file permissions (777) and your hoster added some security checks to avoid this. Try to lower permissions.

Another problem can occur if you're using .htaccess files using UTF-8 codification with Byte-Order Mark (BOM). Reencode your .htaccess files properly without BOM to solve this.

It may happen if you are using Fedora with SElinux and copied the dokuwiki files from your home directory. To correct it, run “restorecon -r .” as root on the website dokuwiki directory

Some people reported a 500 error when creating new users or changing passwords on certain hosters. Try to change the passcrypt option from smd5 to md5.

If you use discussion plugin and a 500 error occures after submit a comment, insert a recipient email address at notify. Maybe this is a bug in 2009-02-14.

This error can also manifests itself as a PHP error. Try adding the code below to one of your PHP files such as local.php, then checking the error log file it generates.

ini_set('log_errors', 1);
ini_set('error_log', 'errorlog.txt');

PHP7 on Linux requires the addition of php7.0-xml which is not installed by default. Otherwise you'll get 500 errors when editing/creating. (and call to undefined function utf8_decode() in /var/log/apache2/error.log)

# on debian: 
# sudo apt-get install php7.0-xml
# sudo service apache2 restart

Some combinations of plugins seem to cause this behaviour. If in doubt, disable user-installed plugins. If this restores access to your Wiki, make sure all of your plugins are update-to-date using Plugin Manager. If you cannot access your Admin/Plugin Manager page but you do have access to the server's filesystem (e.g. by ssh), then you can disable plugins by editing conf/plugins.local.conf or creating an empty file called 'disabled' in each plugin's directory. Each time you disable an extra plugin, refresh your browser to see if the 500 error has gone away. On *nix, something like either of the below should do the trick to disable plugin 'pluginname':

# cd /path/to/dokuwiki/root/lib/plugins/pluginname
# touch disabled

or in conf/plugins.local.conf:

$plugins['pluginname'] = 0;

Make sure you don't have conflicting values between the two! plugins.local.conf overrides 'disabled' files.