ttbb

thanks a lot for your answer with your directives and tipps, which fortunately aren’t necessary anymore 🙂
the cause for the white screen was found located outside of the wp installation on my webserver where an erroneous .htaccess one level up with a directive routing the path */admin/data to 404, which by chance affects the /root/my_wp_installation/wp-content/plugins/woocommerce/assets/client/admin/data/index.js which was identified as missing and causing the unfinished loading of the wc setup wizard (the page was mostly loaded, but stayed invisible).