Getting Error (Warning) Message when trying to save content to existing Page

When Adding content to a page I am getting this white page with the following content:

Cache Succeddfully Cleared

Cache Succeddfully Cleared

Warning: Cannot modify header information - headers already sent by (output started at /home/nwhcmud1/public_html/wp-content/plugins/better-wp-varnish/better-wp-varnish.php:201) in /home/nwhcmud1/public_html/wp-includes/pluggable.php on line 876

(Hum, also notice the misspelled word Sucessfully in the error message)

Flavor of Varnish is: Varnish Version: 3.0.3-unixy

The ‘Varnish – Clear All’ button in the Admin page works without issue.

Any help as to the cause of the inability to add changes to pages (haven’t tried changing posts yet) would be appreciated.

https://www.ads-software.com/extend/plugins/better-wp-varnish/