internal server error after deleting thumbnails image-style I have an internal server error on my drupal site only when I log in, when logged out everything is fine.

I was having problems with the default image-styles, they would not work (no thumbnail preview) so I created a new style (thumbnail2), deleted the default thumbnail style and replaced it with thumbnail2 style.

Any ideas how I recover from this?

So 2 problems:
1. get access to admin again
2. get default images styles to work

Server log:
Symfony\Component\Routing\Exception\RouteNotFoundException: "Route "view.media.media_page_list" does not exist."
After some googling I saw a similar error on Drupal.org

https://www.drupal.org/node/2836162

Check the last few comments. It might be related to Media Entity