Make sure of the following:
/usr/local/centovacast/centovacast.conf
Find (Near the bottom of the file):
USE_WEB_PROXY=false
Change to:
USE_WEB_PROXY=true
While in SSH run the following:
/usr/local/centovacast/sbin/setproxy on
Be sure you are not getting any error message, and that you get a success message.
Then when you go to any account, under Settings > Limits
Port 80 Proxy should then be in bold and usable, change to "Permitted", click Update, restart stream if it is currently running.