2020-03-26 16:09:09 [XnzTmwpAAEQAAJUGnSwAAADI] mw1273 cswiki 1.35.0-wmf.24 exception ERROR: [XnzTmwpAAEQAAJUGnSwAAADI] /w/index.php?title=Wikipedistka:Zorka_Sojka/D%C3%ADlna/Jan_Kotek&action=delete JobQueueError from line 106 of /srv/mediawiki/php-1.35.0-wmf.24/extensions/EventBus/includes/JobQueueEventBus.php: Could not enqueue jobs: Unable to deliver all events: 504: Gateway Timeout {"exception_id":"XnzTmwpAAEQAAJUGnSwAAADI","exception_url":"/w/index.php?title=Wikipedistka:Zorka_Sojka/D%C3%ADlna/Jan_Kotek&action=delete","caught_by":"mwe_handler"}
This happened when trying to delete a page at Czech Wikipedia. It first hanged out for ~10 seconds, and then threw this fatal error. Refreshing fixed it.