theme error

Fatal error: Cannot redeclare widget_mdv_most_commented_per_cat() (previously declared in /home/content/t/a/h/tahoerealtor1/html/wp-content/plugins/atahualpa/functions/bfa_popular_in_cat.php:22) in /home/content/t/a/h/tahoerealtor1/html/wp-content/themes/atahualpa/functions/bfa_popular_in_cat.php on line 78

anybody know how to resolve this one. I have tried to reload several times to the ftp same result. I install the plugin on the ftp but it won’t activate.