There were problems with recent versions of MediaWiki. Because the updates caused problems the developers rolled back to an earlier version. Some updates and new functions will come later than planned.
Some services will not work for a short period of time from 07:00 UTC on 17 February. There might be problems with new short links, new translations, new notifications, adding new items to your reading lists or recording email bounces. This is because of database maintenance.
The new version of MediaWiki will be on test wikis and MediaWiki.org from 16 February. It will be on non-Wikipedia wikis and some Wikipedias from 17 February. It will be on all wikis from 18 February (calendar).