Unable to open /var/www/admin/lang/

[yojoe]

I think it's a problem with path to getsimple's admin/lang
You have uploaded your site to /var/www/admin/data/www/test.site.com, thus that may be the problem.
Try to create a soft link inside /var/www/admin/ to /var/www/admin/data/www/test.site.com/admin/lang
or upload lang directory to /var/www/admin and see if another problem with path to GS data appears.