Hello.
There's only one custom namespace on oecumene.org — «Архив» (ns-1746).
Can you recreate it with following code for LocalSettings.php?
define("NS_ARCHIVE", 200); define("NS_ARCHIVE_TALK", 201); $wgExtraNamespaces[NS_ARCHIVE] = "Архив"; $wgExtraNamespaces[NS_ARCHIVE_TALK] = "Обсуждение_архива"; define("NS_PORTAL", 202); define("NS_PORTAL_TALK", 203); $wgExtraNamespaces[NS_PORTAL] = "Портал"; $wgExtraNamespaces[NS_PORTAL_TALK] = "Обсуждение_портала";