Ahh. Now I get it. Many thanks
I think there might be a bug with the choice of language. If you use another language than english (swedish for instance), the plugin will show the text in spanish.
A future request would be to include a language picker in the options page.
Thanks
I realise that the custom fields doesn’t seem to work either. Very strange
I’ve been wrestling with this problems for days, trying all the suggested fixes. For me it turns out it’s a plugin that is breaking the visual editor, Dagon Design Sitemap Generator. It seem to be something wrong with the language settings which causes a header error.