2.0.17 can not add a language

[captcha]

I installed a 2.0.17 SMF.
I tried to add a language (a couple of days ago and today), it always showed:
"The Simple Machines site is not responding. Please try again later."
I tried to ftp the language files to the server in corresponding directories, but my SMF can not find the new language.
Is there anyway to install a new language?

[vbgamer45]

Did you upload the language files to themes/default/languages ?

[Hatshepsut]

I think you need to upload language file to your forum directory and then extract its content.

[captcha]

Did you upload the language files to themes/default/languages ?

The problem solved, the index.php file under theme directory was not copied.