Goodreads icon broken?

Hello Lars,

Thank you for reporting this!
Simple Author Box uses FontAwesome 4.7 which does not have the Goodreads icon integrated yet, as it was introduced in 5.0.
I have reported this to our developers and when they will fix this in our future update.
In the meantime, I can give you a code to add there a book icon so it does not remain empty. Would that work for you?
If yes, please go to Appearance > Customize > Additional CSS and add this code:

.saboxplugin-wrap .saboxplugin-socials .saboxplugin-icon-color.fa-goodreads::before {
    content: '\f02d';
}

You can follow the progress regarding this here:
https://github.com/MachoThemes/simple-author-box/issues/70

All the best,
Mihaela