Wordpress multisite get current user function not working in subdomains

Hi,

i have recently upgrade the wordpress to multisite in my clients site..

for your reference here is the link...
realestate.nyasatimes.com

even after i logged as admin, current user always shows as 0.. i dont know where the issue was.. was googling for last 6 hours and tried some thing nothing helped me

so finally i am here to seek your help..if you came across this issue.. please share and help me...
here is .htaccess file for your reference

RewriteEngine On
#redirect to www for the main site
RewriteCond %{HTTP_HOST} ^nyasatimes\.com
RewriteRule ^ http://www.nyasatimes.com/%{REQUEST_URI} [L,R=301]

RewriteBase /
RewriteRule ^index\.php$ - [L]

# uploaded files
RewriteRule ^files/(.+) wp-includes/ms-files.php?file=$1 [L]

RewriteCond %{REQUEST_FILENAME} -f [OR]
RewriteCond %{REQUEST_FILENAME} -d
RewriteRule ^ - [L]
RewriteRule . index.php [L]

Code (markup):

 

i had the same problem. i solved changing all psw and admin user completely different.