Author user role, Gutenberg add picture from someone else, rest_forbidden_context crash, image size crash

[debricon]

Login as a user with role Author (important, user editor works normaly).

Create post, add existing picture from the gallery to your article.
In the console you'll get an error :

/wp-json/wp/v2/media/11133?context=edit&_locale=user
{code: "rest_forbidden_context",

and you can't change the image size.

• User roles Editor and Admin are not affected.
• Uploaded picture by the Author are not affected.

[TimothyBlynJacobs]

I think this needs to be reported in the Gutenberg repository: ​https://github.com/wordpress/gutenberg It looks like the error is client side, an author legitimately wouldn't have access to the media gallery.