You may randomly get an error 500 or 503 if you visit the wiki at the moment.
"We are aware of short outages at approximately 8am and 9am UTC. Please see https://phabricator.miraheze.org/T6426 for updates and your guess is as good as mine as to whether a repeat will happen at 10am." -Miraheze
Clearing your cookies or appending ?action=purge at the end of the URL may fix the error 500.
This incident is now resolved.