This notice will be fixed in next version, it is not fatel error so it can not conflict with any functionality.
If it is being desplayed on your web-page, I think you have incorrect setting for debugging in wp-config.php. Below are ideal settings for debugging in wp-config.php and you should change this only when you need to debug the code:
define( ‘WP_DEBUG’, false );
define( ‘WP_DEBUG_LOG’, false );
define( ‘WP_DEBUG_DISPLAY’, false );
@ini_set( ‘display_errors’, 0 );
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