English (US) is not available. The locale en_US is not supported on your server.

what's wrong?

What the message says, your server does not support the english US locale. But that should not really matter since english is the default language you would get to see even if you had no language selected. Please see also here:
http://www.zenphoto.org/2008/08/troubleshooting-zenphoto/#24

Under 5. you can download a script to see what locales your server supports.

infactly,it can be changed to english or other languages,but it will also accord to this error,except my computer language. is that correctly?

in 1.1.7,it will be freely changed to all language without that error.

Do you have the en_US folder (it is okay that it is empty) within the zp-core/locale folder?

yes,have all defalut language folders

Did you run the script acrylian suggested? What language locales does your server support? If your server does not support the locale en_US you will get this error if you select English (US).

Http Accept Languages:
Key code coef morecode fullcode
1.0-zh zh 1.0 cn zh_cn

Supported locales:

it seems only sopport zh_cn,it depends on computer language?can not be switched freely?

That's a server configuration. I don't know what is involved in installing a new locale. In your case, no locales are supported. The first set of output is the prefered language your browser requests.

I would suggest to contact your ISP about that.

I just test on localhost.it has no error in Ver1.1.7

That would be because there was no error message on 1.1.7. The `setlocale()` still failed. We just did not have any indication of why the language selection did not work.

It seems depends on computer language ,when change to other language ,it will cause error,but it had be changed,just display that error.

Well, it is an error to change to a language which is not supported on the server.

when do you fix it?

I am seeing this error too. Do I need to configure something?

"Locale functionality is not implemented on your platform or the specified locale does not exist. Language translation may not work."

And I cannot set up the language.
I am working with the most current nightly build.

See #3 http://www.zenphoto.org/2008/08/troubleshooting-zenphoto/#24

The fix is to configure the server correctly. However, you can also ignore the error message.

I am testing on windows,how to configure it.

everything I know about configuring is shown in the link above.

Hi, I'm having the same problem with en_us, i.e.:
`Locale functionality is not implemented on your platform or the specified locale does not exist. Language translation may not work.`

Furthemore I have a warning when I try to change the language (from/to whatever) in amin>options>gallery configuration:
`
Notice: Undefined variable: locale in /home/web/www.*****.it/www/zp-core/admin-options.php on line 226

Warning: Cannot modify header information - headers already sent by (output started at /home/web/www.******.it/www/zp-core/admin-options.php:226) in /home/web/www.antonioranesi.it/www/zp-core/admin-options.php on line 417
`
but after a refresh in browser everything goes ok (?)

I tryed to run the list_locales.php script but I received the following warning:
`Warning: system() has been disabled for security reasons in /home/web/www.*******.it/www/list_locales.php on line 4`

Anyway everything works fine for the languages with their own .po files and, of course, english still works after the error message.
I suppose that a workaround could be to disable these warnings, at least in the front end, to allow visitors to change language.
Am I true? If so what is the best way to disable warnings?

Ciao
bic

It would seem you are not using a current version of Zenphoto since the above line has no reference to the variable `locale` nor does any line nearby. Perhaps you should upgrade.

But anyway, without the locale functionality on your server other language based things will not work such as PHP based strings like dates. So, the best solution is to work with your provider to get their configuration straightened out.