admin/environment/php extension/iconv
From MoodleDocs
To enable iconv in Windows package installations of Moodle:
- Open the php.ini file found in the moodle/apache/bin folder
- Find the line:
;extension=php_iconv.dll
- Remove the
;
at the beginning of the line - Restart apache for the change to take effect.
This page needs to be enhanced by adding corresponding instructions for other kinds of Moodle installations.