Avada theme - Fatal error: Uncaught Error: Call to a member function get_source_language_code()...

Overview of the issue

If you try to translate an Element created with Avada library from WPML > Translation Management page, you will find the following PHP error:

PHP Fatal error: Uncaught Error: Call to a member function get_source_language_code() on bool in .../wp-content/plugins/sitepress-multilingual-cms/vendor/wpml/tm/inc/functions-load.php:496
Stack trace:
#0 [internal function]: wpml_tm_create_ATE_job_creation_model()
#1 .../wp-content/plugins/sitepress-multilingual-cms/vendor/wpml/fp/core/Fns.php(164): array_map()
#2 [internal function]: WPML\FP\Fns::WPML\FP\{closure}()
#3 .../wp-content/plugins/sitepress-multilingual-cms/vendor/wpml/fp/core/functions.php(152): call_user_func_array()
#4 [internal function]: WPML\FP\Fns::WPML\FP\{closure}()
#5 .../wp-content/plugins/sitepress-multilingual-cms/vendor/wpml/collect/src/Illuminate/Support/Traits/Macroable.php(56): call_user_func_array()
#6 .../wp-content/plugins/sitepress-multilingual-cms/vendor/wpml/tm/classes/ATE/Hooks/class-wpml-tm-ate-jobs-actions.php(141): WPML\FP\Fns::__callStatic()
#7 .../wp-incl in .../wp-content/plugins/sitepress-multilingual-cms/vendor/wpml/tm/inc/functions-load.php on line 496

Workaround

Please, make sure of having a full backup of your site before proceeding.

• Open …/wp-content/plugins/fusion-builder/inc/class-fusion-builder-library.php file.
• Change:

  		add_action( 'wp_loaded', [ $this, 'register_layouts' ] );
  

• For

  		add_action( 'init', [ $this, 'register_layouts' ] );