Cannot Activate Account - Not Sure What Plug-in

I took my site for a test drive today. Signing up worked just fine but when I clicked on the link in the email to validate the account, I received the following message:

Fatal error: Cannot redeclare bp_group_email_localization() (previously declared in /home/artistsm/public_html/wp-content/plugins/bp-group-email/bp-group-email.php:54) in /home/artistsm/public_html/wp-content/plugins/bp-group-email/bp-group-email.php on line 55

The site is http://artistsmall.com/

How do I fix this?

LA Lemire