Q: yii2 basic move to apache 2 ubuntu give a blank page Basically, I develop yii2 using basic template in windows 10 machine is no problem. But now, i move on to develop this yii2 app into ubuntu 16.04
I put yii_folder into /var/www/html/yii_basic, then I access it into
localhost/yii_basic/web, sadly it view a  blank page.
I have no idea,
check .htaccess is no problem in yii_basic/web folder,
enable mod_rewrite also.
then I try to check it by composer,
It gives me :
Problem 1
- codemix/yii2-excelexport 1.0.1 requires phpoffice/phpexcel 1.* -> satisfiable by phpoffice/phpexcel[1.8.1, 1.7.9, 1.8.0].
- codemix/yii2-excelexport 1.0.0 requires phpoffice/phpexcel 1.* -> satisfiable by phpoffice/phpexcel[1.8.1, 1.7.9, 1.8.0].
- codemix/yii2-excelexport 1.0.1 requires phpoffice/phpexcel 1.* -> satisfiable by phpoffice/phpexcel[1.8.1, 1.7.9, 1.8.0].
- phpoffice/phpexcel 1.7.9 requires ext-xml * -> the requested PHP extension xml is missing from your system.
- phpoffice/phpexcel 1.8.1 requires ext-xml * -> the requested PHP extension xml is missing from your system.
- phpoffice/phpexcel 1.8.0 requires ext-xml * -> the requested PHP extension xml is missing from your system.
- phpoffice/phpexcel 1.8.1 requires ext-xml * -> the requested PHP extension xml is missing from your system.
- Installation request for codemix/yii2-excelexport * -> satisfiable by codemix/yii2-excelexport[1.0.0, 1.0.1].

To enable extensions, verify that they are enabled in those .ini files:
- /etc/php/5.6/cli/php.ini
- /etc/php/5.6/cli/conf.d/10-mysqlnd.ini
- /etc/php/5.6/cli/conf.d/10-opcache.ini
- /etc/php/5.6/cli/conf.d/10-pdo.ini
- /etc/php/5.6/cli/conf.d/20-calendar.ini
- /etc/php/5.6/cli/conf.d/20-ctype.ini
- /etc/php/5.6/cli/conf.d/20-exif.ini
- /etc/php/5.6/cli/conf.d/20-fileinfo.ini
- /etc/php/5.6/cli/conf.d/20-ftp.ini
- /etc/php/5.6/cli/conf.d/20-gettext.ini
- /etc/php/5.6/cli/conf.d/20-iconv.ini
- /etc/php/5.6/cli/conf.d/20-json.ini
- /etc/php/5.6/cli/conf.d/20-mbstring.ini
- /etc/php/5.6/cli/conf.d/20-mysql.ini
- /etc/php/5.6/cli/conf.d/20-mysqli.ini
- /etc/php/5.6/cli/conf.d/20-pdo_mysql.ini
- /etc/php/5.6/cli/conf.d/20-phar.ini
- /etc/php/5.6/cli/conf.d/20-posix.ini
- /etc/php/5.6/cli/conf.d/20-readline.ini
- /etc/php/5.6/cli/conf.d/20-shmop.ini
- /etc/php/5.6/cli/conf.d/20-sockets.ini
- /etc/php/5.6/cli/conf.d/20-sysvmsg.ini
- /etc/php/5.6/cli/conf.d/20-sysvsem.ini
- /etc/php/5.6/cli/conf.d/20-sysvshm.ini
- /etc/php/5.6/cli/conf.d/20-tokenizer.ini
- /etc/php/5.6/cli/conf.d/20-xdebug.ini

Please advise ehat should I do.

A: Install missing PHP extension obviously.
sudo apt-get install php5.6-xml


A: Try to debug with this code inside index.php
ini_set('error_reporting', E_ERROR);
register_shutdown_function("fatal_handler");
function fatal_handler() {
    $error = error_get_last();
    echo("<pre>");
    print_r($error);
}

Your php extension are not installed or configure.
