Error While Installing Application

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I was trying to install the application in my localhost in a separate machine (ubuntu)

My Environment:

Installed version: 0.8

PHP:

PHP 7.2.5-0ubuntu0.18.04.1 (cli) (built: May  9 2018 17:21:02) ( NTS )
Copyright (c) 1997-2018 The PHP Group
Zend Engine v3.2.0, Copyright (c) 1998-2018 Zend Technologies
    with Zend OPcache v7.2.5-0ubuntu0.18.04.1, Copyright (c) 1999-2018, by Zend Technologies

mysql:

mysql  Ver 14.14 Distrib 5.7.22, for Linux (x86_64) using  EditLine wrapper

Apache:

Server version: Apache/2.4.29 (Ubuntu)
Server built:   2018-04-25T11:38:24

After the application is placed in web root directory /var/www/html and when I tried to open https://localhost/razor/web/ or https://localhost/razor/web/index.php I get this blank page

Error_log:

[Tue May 15 12:15:30.331943 2018] [php7:error] [pid 3670] [client 127.0.0.1:58196] PHP Fatal error:  Uncaught Error: [] operator not supported for strings in /var/www/html/razor/web/system/core/Router.php:287\nStack trace:\n#0 /var/www/html/razor/web/system/core/Router.php(228): CI_Router->_validate_request(Array)\n#1 /var/www/html/razor/web/system/core/Router.php(198): CI_Router->_set_request(Array)\n#2 /var/www/html/razor/web/system/core/Router.php(161): CI_Router->_set_default_controller()\n#3 /var/www/html/razor/web/system/core/CodeIgniter.php(174): CI_Router->_set_routing()\n#4 /var/www/html/razor/web/index.php(202): require_once('/var/www/html/r...')\n#5 {main}\n  thrown in /var/www/html/razor/web/system/core/Router.php on line 287
[Tue May 15 12:20:32.040331 2018] [php7:error] [pid 3671] [client 127.0.0.1:58224] PHP Fatal error:  Uncaught Error: [] operator not supported for strings in /var/www/html/razor/web/system/core/Router.php:287\nStack trace:\n#0 /var/www/html/razor/web/system/core/Router.php(228): CI_Router->_validate_request(Array)\n#1 /var/www/html/razor/web/system/core/Router.php(198): CI_Router->_set_request(Array)\n#2 /var/www/html/razor/web/system/core/Router.php(161): CI_Router->_set_default_controller()\n#3 /var/www/html/razor/web/system/core/CodeIgniter.php(174): CI_Router->_set_routing()\n#4 /var/www/html/razor/web/index.php(202): require_once('/var/www/html/r...')\n#5 {main}\n  thrown in /var/www/html/razor/web/system/core/Router.php on line 287
[Tue May 15 12:22:33.273855 2018] [php7:error] [pid 1081] [client 127.0.0.1:58312] PHP Fatal error:  Uncaught Error: [] operator not supported for strings in /var/www/html/razor/web/system/core/Router.php:287\nStack trace:\n#0 /var/www/html/razor/web/system/core/Router.php(228): CI_Router->_validate_request(Array)\n#1 /var/www/html/razor/web/system/core/Router.php(198): CI_Router->_set_request(Array)\n#2 /var/www/html/razor/web/system/core/Router.php(161): CI_Router->_set_default_controller()\n#3 /var/www/html/razor/web/system/core/CodeIgniter.php(174): CI_Router->_set_routing()\n#4 /var/www/html/razor/web/index.php(202): require_once('/var/www/html/r...')\n#5 {main}\n  thrown in /var/www/html/razor/web/system/core/Router.php on line 287
[Tue May 15 12:22:40.760036 2018] [php7:error] [pid 1084] [client 127.0.0.1:58320] PHP Fatal error:  Uncaught Error: [] operator not supported for strings in /var/www/html/razor/web/system/core/Router.php:287\nStack trace:\n#0 /var/www/html/razor/web/system/core/Router.php(228): CI_Router->_validate_request(Array)\n#1 /var/www/html/razor/web/system/core/Router.php(198): CI_Router->_set_request(Array)\n#2 /var/www/html/razor/web/system/core/Router.php(161): CI_Router->_set_default_controller()\n#3 /var/www/html/razor/web/system/core/CodeIgniter.php(174): CI_Router->_set_routing()\n#4 /var/www/html/razor/web/index.php(202): require_once('/var/www/html/r...')\n#5 {main}\n  thrown in /var/www/html/razor/web/system/core/Router.php on line 287
[Tue May 15 12:23:49.929805 2018] [php7:error] [pid 1085] [client 127.0.0.1:58326] PHP Fatal error:  Uncaught Error: [] operator not supported for strings in /var/www/html/razor/web/system/core/Router.php:287\nStack trace:\n#0 /var/www/html/razor/web/system/core/Router.php(228): CI_Router->_validate_request(Array)\n#1 /var/www/html/razor/web/system/core/Router.php(198): CI_Router->_set_request(Array)\n#2 /var/www/html/razor/web/system/core/Router.php(161): CI_Router->_set_default_controller()\n#3 /var/www/html/razor/web/system/core/CodeIgniter.php(174): CI_Router->_set_routing()\n#4 /var/www/html/razor/web/index.php(202): require_once('/var/www/html/r...')\n#5 {main}\n  thrown in /var/www/html/razor/web/system/core/Router.php on line 287