Error message on installation

Hello!

We get an error message during the installation.

Fatal error: Uncaught Error: Class ‘VIWEC\INCLUDES\Email_Samples’ not found in /mnt/web001/e2/05/56861305/htdocs/STRATO-apps/wordpress_01/app/wp-content/plugins/woocommerce-email-template-customizer/woocommerce-email-template-customizer.php:110
Stack trace:
#0 /mnt/web001/e2/05/56861305/htdocs/STRATO-apps/wordpress_01/app/wp-includes/class-wp-hook.php(303): WooCommerce_Email_Template_Customizer->viwec_activate()
#1 /mnt/web001/e2/05/56861305/htdocs/STRATO-apps/wordpress_01/app/wp-includes/class-wp-hook.php(327): WP_Hook->apply_filters()
#2 /mnt/web001/e2/05/56861305/htdocs/STRATO-apps/wordpress_01/app/wp-includes/plugin.php(470): WP_Hook->do_action()
#3 /mnt/web001/e2/05/56861305/htdocs/STRATO-apps/wordpress_01/app/wp-admin/plugins.php(193): do_action()
#4 {main} thrown in /mnt/web001/e2/05/56861305/htdocs/STRATO-apps/wordpress_01/app/wp-content/plugins/woocommerce-email-template-customizer/woocommerce-email-template-customizer.php on line 110

We also tried to disable all other plugins. Unfortunately it did not help.

Can you please help us. Maybe you know what the problem is.

With kind regards

Andrej Brockmeier