Reproduce when installing a new mw, at one step the list of authors of MW are shown ending with 'others' pointing to an invalid link.
Call to SpecialVersion::getCopyrightAndAuthorList() in WebInstallerPage.php leads to generation of invalid link using
wfMessage( 'version-poweredby-others' )->text() . ']]'
as the wiki is not even installed. Instead it should point to a source which already exists, maybe mw.org/Special:Version ?