Failed to load plugin url: ……../wp-includes/js/tinymce/lang

Try downloading WordPress again, access your server via SFTP or FTP, or a file manager in your hosting account’s control panel, and delete then replace your copies of everything on the server except the wp-config.php file and the /wp-content/ directory with fresh copies from the download. This will effectively replace all of your core files without damaging your content and settings.

Some uploaders tend to be unreliable when overwriting files, so don’t forget to delete the original files before replacing them.

I’ve noticed the error recently and came up with a quick fix to it. A simple plugin that basically copies locale files into the includes directory. Very preliminary but has done the trick for me so far.

Load languages from here and copy them into the plugin’s langs directory. I’ve included French (fr_FR.js) by default as this is what I needed, but feel free to use it as you see fit.

Word of advice, though, once this plugin has run, I suggest you disable it as it will continuously check for the existence of those locales for no particular reason; just a little performance tip.

• This reply was modified 7 years, 5 months ago by davewoodhall.

Thanks Dave! I had to download the Norwegian language file and copy it over to the folder. It seems to be working now. (No new error message..)