There was an issue with a file not committing to wordpress’ SVN system for plugin updates.
To temporarily resolve the issue you can either do ONE of three things :
Remove the plugin folder wp-content/plugins/shift8-cdn and re-install from scratch
Edit the file wp-content/plugins/shift8-cdn/shift8-cdn.php and comment line 17 out.
So line 17 :
- Download the latest version (1.48) and overwrite the entire wp-content/plugins/shift8-cdn folder with the downloaded copy