Very weird issue. I’ve setup a dozen sites on WP with the Basel theme and this has never happened. I installed the theme and build my first page on the backend, but on the frontend the page is literally just white. I’m sure it’s something obvious.
Could you please try to enable wp debug in the wp-config.php file in your website’s root folder? It should show the PHP error that causes this problem.
More information about the debug mode and instruction how to enable it you can find the official WordPress documentation https://codex.wordpress.org/WP_DEBUG