WordPress SEO plugin returns the error "WordPress didn't return a valid path to your upload directory, please make sure your upload path is set correctly" on the plugin Dashboard.
The Problem: The plugin is trying to create a sub-directory in uploads for the wpseo directory. The plugin correctly checks to see if the uploads directory is available. If not, it generates the error. If it is present it creates the wpseo directory.
Suggested fix: The plugin should create the uploads directory, based on the default or custom value set in Media under Settings.