User blog comment:Rupert Giles/Layout Changes: Breakpoints and Typography/@comment-25704994-20150519172302/@comment-126761-20150519174743

I do apologise if you're running into bugs - but today's changes should generally only have had some effects on page layouts, mostly affecting those with larger screens. Some laptop and tablet users especially may barely notice any differences at all.

Certainly it should not be breaking the ability to edit, nor cause big problems for article content (at least, not beyond what would already have existed for many users on smaller screens).