Normally when editing a page in the Page: namespace, the header, body and footer sections are visually separated by a blue border, like in this image.
However, recently, on editing a Page: these borders momentarily appear but then vanish, so that the left of the window is entirely white save for the text being edited and the labels for the header, body and footer.
This is happening to me on Safari. Other users have reported the problem at the English Scriptorium.
@BethNaught; Removing tags Contributors-Team and Editing-team as it is up to teams which tasks they want to have on their workboard (and as they do not maintain this software stack).
Change 426632 had a related patch set uploaded (by Tpt; owner: Tpt):
[mediawiki/extensions/ProofreadPage@master] Keeps background color behind WikiEditor textareas in Page: pages editing UI
Change 426632 merged by jenkins-bot:
[mediawiki/extensions/ProofreadPage@master] Keeps background color behind WikiEditor textareas in Page: pages editing UI
in addition, the "page body" field seems to have a limited size with a scroll bar, and the "Footer" field seems to expand to fill page even when empty