When sharing a URL on LinkedIn, you may find that the share box shows only a grey image with the website’s domain name. LinkedIn is aware of the issue and here is their response.
Added 36 options from the Pro version General settings page back into the Free version, new “unhide / show all options” link in metaboxes, replaced the ‘Free to Pro version’ self-update feature by a new “NextGEN Facebook (NGFB) Pro Update Manager” Free extension plugin.
Fixed saving of WPSSO options under the WordPress “Settings” menu, added new “Image Dimensions” and “Website / Business Social Accounts” settings pages.
WPSSO v2.8 includes support for Google’s author (Person) and publisher (Organization) social profiles markup in schema.org JSON-LD format.
Setting Up Open Graph Basics in WordPress Social Sharing Optimization. This video will show you how to control your Open Graph Data through WPSSO, as to more accurately share your website’s content.