It seems to be al naguage related error.
Is your site in english or another language ?
If so, does the error also happens in english ?
If it doesn't happen in englich, check your translated language files syntax
Also , I found similar error here
forum.joomla.org/viewtopic.php?f=624&t=838977
and many other forums
and it seems the server was involved
- Need help? Post the URL of the related page (eventualy as confidential info), it will help solve your issue faster.
- An error, notice or warning? report the exact message including the line number
- If you get a white page , enable error reporting and / or check your server error logs.