In Ubuntu, the default setting for PHP is not to display the error message, if the program error will show "Unable to process this request error", which is very inconvenient in the development environment.
Actually, we just need to edit the Apache configuration file.
1. My Apache configuration file directory is/etc/apache2/apache2.conf
sudo vim/etc/apache2/apache2.conf
Then add the following two lines to the end
Php_flag display_errors on
Php_value error_reporting 2039
2. Restart Apache
sudo service apache2 restart
This completes the display of the error message.
Note: If it is not possible to change the configuration under php.ini (I do not have changes can be displayed, because the code added above is already open)
sudo vim/etc/php/7.0/cli/php.ini
Search display_errors default is display_errors=off change to Display_errors=on save quit restart Apache2
Open PHP debug mode under Ubuntu, display error message