It looks like Citation bot is currently blocked because it started blanking articles about a month ago. Let's see if we can help fix or replace it.
https://en.wikipedia.org/wiki/User_talk:Citation_bot - bug reports and discussion about replacing it
https://en.wikipedia.org/wiki/User:Smith609 - The bot's maintainer (semi-active)
https://en.wikipedia.org/wiki/User:Citation_bot/use - Usage instructions
https://code.google.com/p/citation-bot/source/browse/#svn%2Ftrunk - source code (PHP)
https://github.com/ms609/citation-bot - source code (might be more up to data)
https://tools.wmflabs.org/citations/doibot.html - web interface
There are three main parts to the Citation Bot(s): creating cite doi templates through citewatch.php and arxivwatch.php, as User:Citation Bot 2; maintaining citations through cron-doibot.php, as User:Citation Bot 1; and facilitating manual citation entry, through doibot.php (entry point: https://tools.wmflabs.org/citations/doibot.html, as Citation Bot) and text.php (activated from the https://en.wikipedia.org/wiki/MediaWiki:Gadget-citations.js gadget). None of these is currently working.
Dev fork: https://github.com/fhocutt/citation-bot