A fresh install of MediaWiki on an Ubuntu server was throwing memory errors when trying to save certain pages.
mediawiki Fatal error: Allowed memory size [blah] exhausted (tried to allocate [blah])
The fix is simple – increase MediaWiki’s memory size in
/etc/mediawiki/LocalSettings.php, which is only 20MB by default.
I also changed PHP’s maximum allowable memory size in
/etc/php5/apache2/php.ini and reloaded the server.