[סגור] PHP Fatal error when updated WPML to 4.8.6

In our development environment we updated the WPML CMS version from 4.6.5 to 4.8.6. Now we get the following error

PHP Fatal error: Uncaught Error: Class "WPML\UserInterface\Web\Infrastructure\WordPress\CompositionRoot\Config\Api" not found in /var/www/web/app/plugins/wpml-cms/vendor/wpml/wpml/wpml.php:34

Stack trace:

#0 /var/www/web/app/plugins/wpml-cms/sitepress.php(77): require_once()
#1 /var/www/web/wp/wp-includes/class-wp-hook.php(341): {closure}('')
#2 /var/www/web/wp/wp-includes/class-wp-hook.php(365): WP_Hook->apply_filters(NULL, Array)
#3 /var/www/web/wp/wp-includes/plugin.php(522): WP_Hook->do_action(Array)
#4 /var/www/web/wp/wp-settings.php(593): do_action('plugins_loaded')
#5 /var/www/web/wp-config.php(9): require_once('/var/www/web/wp...')
#6 /var/www/web/wp/wp-load.php(55): require_once('/var/www/web/wp...')
#7 /var/www/web/wp/wp-blog-header.php(13): require_once('/var/www/web/wp...')
#8 /var/www/web/index.php(6): require('/var/www/web/wp...')
#9 {main}
thrown in /var/www/web/app/plugins/wpml-cms/vendor/wpml/wpml/wpml.php on line 34

Any idea how to resolve this?