Can’t edit calendar in backend

Hello there!
I can’t edit the calendar-dates or details on a single page in the backend anymore.

There’s just a big blank white space where the calendar should appear. Whenever I try to edit the date of an event, it just reloads the page without letting me even get to the actual calendar.
It also won’t even let me switch from the ‘text’ to the ‘visual’ view in the text editor.

This has never been an issue before. I also have no clue about javascript, and I haven’t changed anything in the settings.

Will there be an update soon to fix this problem?

Thanks a lot for your help in advance!