Troubleshooting: JavaScript error detected

The Live Composer page builder is coded in JS language. This language is very strict about errors. If any theme or plugin generates a JS error, all the code in our plugin stop working properly. JS errors in third-party plugins are one of the most common problems causing Live Composer to break. 

Important

Starting with 1.1  version we integrated a debug window showing details about any JS-errors on your page. This information will help users to identify the problematic plugins and provide us with more information if they contact us for support.

How to troubleshoot the errors

1
Update the plugin to the last version.
2
Open your website for editing in a private/incognito mode. Check if it's any different.
3
Try to deactivate all the other plugins for a minute and see if Live Composer works as expected? This way you can see if any other plugins cause the issue. 

If there is a plugin conflict, please contact us and third-party plugin development about the issue. Most likely they have a JS-error in their code that breaks Live Composer.

4
Try to activate a default WP theme for a minute and see if Live Composer works as expected? This way you can see if there is a problem with your theme.  If there is a problem with the theme, please contact the theme developer. Most likely there is a JS-error in their code that breaks Live Composer.

5
Try with a different browser. Is any difference?
6
Confirm on WP Admin > Users > Your user the "visual editor" option is not disabled.
7
In some cases, the error may show that important plugin resources are not loaded properly. Please allow the browser to load all the content. Don't try to work while the browser shows that is still loading. 
8
Like the last measure, go to WP Admin > Live Composer > Settings > Performance and disable the cache.

Uncaught TypeError: jQuery(...).mediaelementplayer is not a function

The .mediaelementplayer is a WordPress core file and is used in Live Composer to play video backgrounds for sections. It’s get loaded on every page no matter what. Even when you are not using any videos. Most likely, your theme or a third-party plugin removed the mediaelementplayer registered script using wp_deregister_script function.