There was a problem with some Lua modules on July 22 and 23. Some pages using them did not list them in "what links here". You can fix those pages with a null edit: edit and save the page without making any change.
There was a problem with the abuse filter page on big wikis on July 23. It was due to a code error. 
Changes this week
The new version of MediaWiki will be on test wikis and MediaWiki.org from July 28. It will be on non-Wikipedia wikis from July 29. It will be on all Wikipedias from July 30 (calendar).
You can join the next meeting with the VisualEditor team. During the meeting, you can tell developers which bugs are the most important. The meeting will be on July 28 at 19:00 (UTC). See how to join.