Editors can upload images under “Add New Media” but it won’t let them add/edit the fields: caption, alt, description. I created a new editor role and enabled all capabilities, but it didn’t fix the problem. As Admin, I am able to add/edit this data. Have you seen this before? I need the editors to be able to add captions to their photos.
Yes, I narrowed down the problem further. It seems to be specific to the page restriction. All of my editors are restricted to be able to edit just one page. With this setting, they can edit their one page and upload new media (but unable to edit the metadata, which is my problem). When I turn this setting off (allowing them to edit any page), then the problem goes away and they can edit metadata.
To restrict their editing to just one page, I go to each user profile, and in the Posts/Pages/Custom Post Types Editor Restrictions section, I click the radio button for “Allow” and then enter the page ID number in the field called “with post ID (comma separated).”
When you set edit restrictions for the role or user User Role Editor applies this restriction to all post types including the ‘attachment’ one. WordPress use this post type for the Media Library items.
It’s possible to exclude some post types from this restriction scope with custom filter: