[Plugin: SEO Facebook Comment] It doesn't save my settings

I’ve upload the latest version of the plugin. I add my App Id, app secret, Admin Id, Lanaguage, post number and comments width, I saved the setting and nothing changes. It appears again the same empty form saying ‘SEO Facebook Comments is almost ready, however you MUST insert the App ID, App Secret and Admin ID’.

What am I doing wrongly?

Thanks!

https://www.ads-software.com/extend/plugins/seo-facebook-comments/