Icons not displaying; file size displays

The file size is displaying nicely, but the file type icons are not displaying. I read through other support topics, and realized a mime-types-file is not loading (403 error) by checking the console. I tried changing my theme to 2014 and 2016, deactivating all my plugins, and checking to see if I have a .htaccess file (I don’t), but nothing worked. My site is password protected, so it won’t help to link it there. Is there anything else I can try? Thanks.

https://wordpress.org/plugins/mimetypes-link-icons/