We have been using the "Infinite SEO" plugin since the 4.2.2 release. We have been putting the page title in the appropriate place in the Infinite SEO for every wiki loaded. Since we had to revise every wiki when we re-structured the site (about 1000 wikis), we took the additional step of adding the SEO page title to every wiki.
The Page Title in the Infinite SEO is now disappearing, seemingly in a random manner, with 'blocks' of wikis all loaded within a few hours of each other Infinite SEO Title disappearing.
Yes, I know this sounds absurd. BUT, a similar problem has been happening with links on wiki pages since the 4.2.2 release. One day, the link is fine. The next day, it doesn't work, and I get a 'broken link' message emailed to me. In almost every case, the link is still good (I go to the URL of the link and it is STILL there, but the broken link checker said it was not.) The 'normal' broken link message is a 404, time out, error. However, I also get the 402 (can't find the URL) error on many of them.
These problems have only happened since the new release.
Support Access is enabled.
I can forward you copies of the email messages I have been getting if you need to see them.