The visual editor TinyMCE is no matter js equivalent language of the site.

[hersonrodrigues]

In my case I set for the language of Brazil (pt_BR), but the js that is required is called pt-br.js. Inside the langs folder, there's a file called pt_BR.js which is obviously not found, because the name is very different.

[neilferreira]

I am noticing the same thing.

My website is 404ing on /++plone++static/components/tinymce-builded/js/tinymce/langs/en_EN.js

[petschki]

See #849