Flux Checkout - Fatal error: Uncaught ValueError: Unknown format specifier "t"...

Overview of the issue

If you are using a plugin as Flux Checkout, a fatal error may occur when the WPML String Translation plugin is activated and the admin language is switched to a secondary language:

Fatal error: Uncaught ValueError: Unknown format specifier "t" in .../wp-content/plugins/wpml-string-translation/classes/translations-file-scan/wpml-st-translations-file-registration.php:100

Workaround

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

• Open …/wp-content/plugins/wpml-string-translation/classes/translations-file-scan/wpml-st-translations-file-registration.php file.
• After these lines:

  	private function get_file_path_pattern( $file_path, $original_domain ) {
  		$pathinfo  = pathinfo( $file_path );
  		$file_type = isset( $pathinfo['extension'] ) ? $pathinfo['extension'] : null;
  

• Add this:

  $file_path = str_replace('%', '', $file_path);