Front End VC editor is disabled by default because some theme elements use advanced javascript functionality, and these elements will not be displayed correctly until you save and refresh the page after adding them.
You can still enable the Frontend editor by editing one of these two files:
wp-content/themes/theme_name/framework/modules/visualcomposer/visual-composer-config.php
or
wp-content/themes/theme_name/extendvc/extend-vc.php
And remove the entire 'vc_disable_frontend' function:
if(function_exists('vc_disable_frontend')){
vc_disable_frontend();
}
https://www.screencast.com/t/avtPbDvIn
