Can't edit old posts

Hi! I spent the whole night redesigning my page with page builder and editing some older posts and when I checked in in the morning I suddenly can’t edit any old posts. Nothing happens when I click around. I can edit the text and click update, but I can’t add new media or delete the feature image, for instance. Also, the edit bar for the text does not appear (with the fonts coding etc).
It is working when I want to make a new post. I don’t know what could have happened.