Can't add/edit pages, posts, menu, etc…

Hello,

I’m working on a website for several week and until now I had no trouble adding or editing a page, a post or adding an element to a menu. But since last friday I can’t do that anymore. Every time I try to update or add a page/post it just brings me to the post admin page. And when I try to add an element to a menu it just doesn’t do anything.

I tried deactivatating all plugins and then activate them one by one but the problem remains. Same thing if I change the theme.

I also tried to change the memory limit but still no luck.

Last thing, I saw no php errors when I activated the wp_debug.

Has anyone any idea what the problem might be?

Thank You.