Cannot acces my admin receiving Warning message

My WP blog is hosted on GoDaddy. I received the following message. I installed the update 2.7.1 and am still receiving this message. I cannot access the admin section. Please advise.

Warning: Cannot modify header information – headers already sent by (output started at /home/content/r/t/h/rthastarsite/html/Eco Shoe Source/wp-content/plugins/wordpress-blog-stat/stat.php:37) in /home/content/r/t/h/rthastarsite/html/Eco Shoe Source/wp-includes/pluggable.php on line 850

Thanks you