If you are using a custom htaccess file from Admin Tools in Joomla 3.x is very possible you find some issues with the ActiveHelper Live Chat button. This htacecss file is very complex and can cause some issues with the deploy of the chat module.
The solution is to change some of the rules in order to allow the deploy of the chat button without decrease the security of your site. We found four rules that can cause problems with the Live Chat button, but remenber can be more depending of the complex of the file.
Rule 1 : RewriteRule ^(components|modules|templates|images|plugins|media|libraries|media/jui/fonts)/ - [L]
Rule 2 : RewriteRule (.*\.php)$ - [L]
Rule 3 : Header set X-Content-Security-Policy "allow 'self';"
Rule 4 : RewriteRule .* - [L]