This is my note for having error in using One click demo import on WordPress
the error was : Internal server error (500)
if you use VPS and Apache as web server, check your error log with :
sudo tail -f /var/log/apache2/error.log
it will said :
PHP Fatal error: Uncaught Error: Class ‘XMLReader’ not found in /var/www/…..
then you need to install php-xml with :
sudo apt-get install php-xml ( Ubuntu 18.04 ).
After the installation is finish, you have to do
sudo systemctl reload apache2 and that’s it !
refesh your page, try to import again. enjoy