There are similar problems in Arabic Wikipedia related to notifications, and visual editor. When you click on the notification icon, it keeps (loading), and never show the notifications. Also, when you use visual editor; the progress bar keeps loading and the editor never get ready. These problems shows up just yesterday. I check what error occurs when click on notifications for example (using F12), and I get this error: "Uncaught TypeError: Cannot read property 'hasOwnProperty' of undefined(…)". These problems occurs only in Arabic wikipedia, I've checked enwiki, commons, and wikidata, and I found no problems.