In most cases, these type of issues are caused by server misconfigurations. Don’t hesitate to check the WordPress prerequisites here: https://wordpress.org/about/requirements/
If your demo is not completely imported (images and/or sections missing), it is probably related with a PHP limit that prevents you to correctly import the demo on your server. In that case, we suggest you to reach your hosting company and ask them to increase this limit for you. If you wish to do it yourself, we suggest you to add the following snippet via FTP at the .htaccess file:
php_value post_max_size 32M
php_value upload_max_filesize 32M
php_value memory_limit 256M
php_value max_execution_time 300
php_value max_input_time 300
php_value session.gc_maxlifetime 86400In case this quick fix has not solved your issue, our complete demo troubleshooting guide might help you to go further: