Rss feed not working

Whenever I try to generate an rss feed using the meta link on the wp page ( try either https://www.compusell.biz/blog or https://www.specialty-art.com/blog) I get the following error:

Warning: Cannot modify header information - headers already sent by (output started at /home/gtwth/public_html/compusell/blog/wp-blog-header.php:1066) in /home/gtwth/public_html/compusell/blog/wp-rss2.php on line 10

Anybody have any suggestions? I have checked both the wp-blog-header.php and the wp-rss2.php file and can’t find anything wrong there I am stumped on this one.
Rick