Screenshot of the bug
I have to enter two blank lines at the top of a page just to see what I'm typing, since the top two lines are hidden by the toolbar. Also, none of the buttons on the toolbar actually work.
This has begun at the same time a change was made to the edit window. The old edit window should be reinstated as the default one until this bug is fixed.
I have added a screenshot of the bugged edit window. The position of the cursor was right under the "Heading" select box, out of reach.