Page list Error

Hello, I’m kindly askin for help here.
As i opened my admin site today and wanted to adjust one of my pages, i clicked on Page list at the user home page and “Page cannot be found” popped up.
As I am the only one owning the website, there can’t be any privacy settings done differently. My website is working normally, i can see every page as a visitor, but i can’t see and update them as logged admin.
I can also create a new page, save it, but can’t visit it later, as the error pops up.
I can also see all of my pages in the Menu settings, so I know, all of them are still there.
I don’t have many pluggins installed, i tried to deactivate them and nothing changed.

So in conclusion: My website is working for every visitor and they can see every page. But I as the only admin can’t adjust any of my pages, because “Page can’t be found” pops up whenever i click on Page list.

Thank you for your suggestions!