The Euclid editor doesn't have any of the buttons around the editor, such as the various header buttons or any formatting things. BBcode also isn't highlighted in the editor, with @ links just showing as plain text instead of being highlighted as previously.
Open any article to write, and the editor is lacking all the buttons
This looks like a local issue with the browser (due to plugins / extensions) have you tried this on a different device and/or browser?
I tried on windows 10, Chrome, Firefox and Edge. All with the same results, as well as firefox on android. They all are lacking the widgets.
I tried changing the interface to the Plato editor, and that all works fine. It's just that the Euclid interface doesn't load the buttons.