A database error has occurred. Did you forget to run maintenance/update.php after upgrading? See: https://www.mediawiki.org/wiki/Manual:Upgrading#Run_the_update_script
Query: SELECT page_id,page_len,page_is_redirect,page_latest FROM `page` WHERE page_namespace = '10' AND page_title = 'Extension_DPL' LIMIT 1
Function: LinkCache::addLinkObj
Error: 1047 WSREP has not yet prepared node for application use (192.168.42.42:3307)