I am getting following warning when trying to install a pack on QA site
Warning: fopen(/moodledata/temp/.htaccess) [function.fopen]: failed to open stream: No such file or directory in /html/lib/setuplib.php on line 1153
Although the pack gets installed properly.
1. Login as an administrator and browse to Settings > Site administration > Language > Language packs.
2. Select select several languages from the list of available languages and click the 'Install selected language pack' button.
3. Check that the languages are now listed as installed language packs and shouldn't generate any warnings.