Hi,
I don't see why it would come from the language file.
And that error message is just a generic error message so it doesn't tell much on why it would happen.
Please try again with the "error reporting" and "debug mode" settings of the Joomla configuration activated.
It might display a better error message on the pages with the issue.
If it does, provide it, otherwise, you'll have to look at the PHP error log of your hosting for the error message corresponding to that issue. You might need to ask your hosting support about that if you don't know how to find it.