Bug – Cannot delete a pdf file

Hello

I have a fresh WordPress install and I try to delete a pdf file by pressing on the red icon. nothing happens

See screenshot http://postimg.org/image/3z48eab5v/

Errors on the console
Deprecated TinyMCE API call: <target>.onBeforeSetContent.add(..)

Url turns into
http://localhost:8888/test/wp-admin/post.php?post=28&action=edit#