Hi,

A blank white screen in Odoo after registration and module selection typically points to a JavaScript or server-side error. Without server access, prioritize client-side troubleshooting: check the browser's developer console for errors, clear cache and cookies, disable extensions, and try a different browser or incognito mode. Ensure a stable network connection.

Contacting Odoo Support is crucial, providing your Odoo version, steps taken, console errors, and troubleshooting already attempted. They can check server logs, investigate module installation, and apply fixes. Also, check for any Odoo status page for known outages and try again later in case of temporary issues.

Hope it helps