White page for install

A blank page means that PHP is crashing, typically due to a function conflict introduced by a plugin or theme.

Try deactivating all plugins. If that resolves the issue, reactivate each one individually until you find the cause.

If that does not resolve the issue, try switching to the Twenty Seventeen theme to rule-out a theme-specific issue (theme functions can interfere like plugins).

Thank you James for your answer.
I deactivate all plugins but it dos not help. I also switch to twenty seventeen theme but no result – still blank page ??

Ok, try downloading WordPress again, access your server via SFTP or FTP, or a file manager in your hosting account’s control panel (consult your hosting provider’s documentation for specifics on these), and delete then replace your copies of everything on the server except the wp-config.php file and the /wp-content/ directory with fresh copies from the download. This will effectively replace all of your core files without damaging your content and settings.

Some uploaders tend to be unreliable when overwriting files, so don’t forget to delete the original files before replacing them.

now it works

thanks a lot