WP 5.0. breaks page builder. See fix here

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Enable debug mode

Sometimes, certain theme functionalities might not work properly (demo import, theme options not saving, etc.) without any error or warning in WordPress dashboard or browser console. To investigate this, you need to enable debugging:

  • using FTP, go to your wordpress installation folder and open wp-config.php
  • search for WP_DEBUG and enable it by changing the argument to "true":
define( 'WP_DEBUG', true );
  • below that, add another line:
define( 'WP_DEBUG_LOG', true );
  • run the faulty action again (demo import, theme options), just like you did before
  • go to /wp-content/ and open debug.log
  • any errors or warnings that occurred during the process will be logged in that file

A common approach to fixing those errors is by copy/pasting the error (only the error, not the file path) to Google and looking for solutions. Most of the time, you'll see that someone already has a fix on stockexchange or similar websites.