This seems to be a javascript issue (yes I cleared my cache, yes tried even with incognito or a different browser, yes disabled all customizations) that is crippling the whole administration. Most of your actions involve an alert being shown to confirm or cancel them but that alert is not working any more. I can't even call for support from the admin (the "Still need help?" button) due to the error in the screenshot. This all started after the latest update to 4.4.9.1

 

 

I would recommend submitting a ticket for support.