Thread:Project:Support desk/Error while installing MediaWiki/reply

This is not a MediaWiki problem.

I would ask in a Redhat forum why installation of the php-xml package does not work. Google also has a lot of hits on this one already: https://www.google.com/search?q=%22install%22+%22Error+Downloading+Packages%22

See also the cross post at http://stackoverflow.com/questions/22542973/mediawiki-not-installing