Thread:Project:Support desk/Can't contact the database server: Access denied for user 'wikiuser'@'localhost' (using password: NO) (localhost))/reply (19)

Your error message shows that MediaWiki does not(!) use any username. Please check that $wgDBuser is spelled and written correctly!

When you are at it, please verify that "ps8293.dreamhost.com" is the correct value for $wgDBserver!