rhel6.5搭建mantis時報錯「INTERNAL APPLICATION ERROR」

參考以前成功搭建mantis時整理的文檔，再次在rhel6.5上搭建mantis時遇到個以前沒遇到過的問題，在搜尋過網上一些文檔後依舊沒能解決，所以在這整理出來，但願有路過的大佬能順便幫忙指點一二。

圖中信息理論上來說是沒有問題的，可是點擊以後開始報錯，以下圖：

操做系統：Redhat 6.5
php版本：7.0
mysql版本：5.6.22 （編譯安裝）
mysql數據庫root密碼爲root
mysql -uroot -proot
mantis版本：mantisbt-2.17.1.tar.gz
mantisbt-2.16.0-dev-master-1e14941.tar.gz ---> 這個版本也試過，也是同樣的報錯，可是上一次成功搭建用的就是這個版本
mantis庫：

create database mantis default character set utf8 collate utf8_general_ci;
grant all privileges on mantis. to 'mantis'@'%' identified by 'mantis';
grant all privileges on mantis. to 'mantis'@'localhost' identified by 'mantis';
grant all privileges on mantis. to 'root'@'%' identified by 'root';
grant all privileges on mantis. to 'root'@'localhost' identified by 'root';
flush privileges;

http日誌中報錯：
/var/log/httpd/error_log
26 [Tue Oct 23 09:30:41 2018] [error] [client 20.20.20.1] File does not exist: /var/www/html/mantisbt/css/admin, referer: http://20.20.20.42/mantisbt/admin/install.php
27 [Tue Oct 23 09:31:27 2018] [error] [client 20.20.20.1] Call to undefined function mysqli_connect_error()\n/var/www/html/mantisbt/core/database_api.php: 588: ADODB_mysqli - - > - ErrorMsg()\n/var/www/html/mantisbt/admin/install.php: 431: - - - - db_error_msg()\n, referer: http://20.20.20.42/mantisbt/admin/install.php
28 [Tue Oct 23 09:31:27 2018] [error] [client 20.20.20.1] File does not exist: /var/www/html/mantisbt/css/admin, referer: http://20.20.20.42/mantisbt/admin/install.php
29 [Tue Oct 23 09:38:54 2018] [error] [client 20.20.20.1] Call to undefined function mysqli_connect_error()\n/var/www/html/mantisbt/core/database_api.php: 588: ADODB_mysqli - - > - ErrorMsg()\n/var/www/html/mantisbt/admin/install.php: 431: - - - - db_error_msg()\n, referer: http://20.20.20.42/mantisbt/admin/install.php
30 [Tue Oct 23 09:38:55 2018] [error] [client 20.20.20.1] File does not exist: /var/www/html/mantisbt/css/admin, referer: http://20.20.20.42/mantisbt/admin/install.php
31 [Tue Oct 23 09:38:58 2018] [error] [client 20.20.20.1] File does not exist: /var/www/html/mantisbt/css/admin, referer: http://20.20.20.42/mantisbt/admin/install.php
32 [Tue Oct 23 09:39:00 2018] [error] [client 20.20.20.1] File does not exist: /var/www/html/mantisbt/css/admin, referer: http://20.20.20.42/mantisbt/admin/install.php
33 [Tue Oct 23 09:39:01 2018] [error] [client 20.20.20.1] File does not exist: /var/www/html/mantisbt/css/admin, referer: http://20.20.20.42/mantisbt/admin/install.php
34 [Tue Oct 23 09:39:25 2018] [error] [client 20.20.20.1] Call to undefined function mysqli_connect_error()\n/var/www/html/mantisbt/core/database_api.php: 588: ADODB_mysqli - - > - ErrorMsg()\n/var/www/html/mantisbt/admin/install.php: 431: - - - - db_error_msg()\n, referer: http://20.20.20.42/mantisbt/admin/install.php
35 [Tue Oct 23 09:39:25 2018] [error] [client 20.20.20.1] File does not exist: /var/www/html/mantisbt/css/admin, referer: http://20.20.20.42/mantisbt/admin/install.php
36 [Tue Oct 23 09:58:15 2018] [error] [client 20.20.20.1] File does not exist: /var/www/html/mantisbt/css/admin, referer: http://20.20.20.42/mantisbt/admin/install.php
37 [Tue Oct 23 09:59:11 2018] [error] [client 20.20.20.1] Call to undefined function mysqli_connect_error()\n/var/www/html/mantisbt/core/database_api.php: 588: ADODB_mysqli - - > - ErrorMsg()\n/var/www/html/mantisbt/admin/install.php: 431: - - - - db_error_msg()\n, referer: http://20.20.20.42/mantisbt/admin/install.php
38 [Tue Oct 23 09:59:11 2018] [error] [client 20.20.20.1] File does not exist: /var/www/html/mantisbt/css/admin, referer: http://20.20.20.42/mantisbt/admin/install.php
39 [Tue Oct 23 10:11:28 2018] [error] [client 20.20.20.1] Call to undefined function mysqli_connect_error()\n/var/www/html/mantisbt/core/database_api.php: 588: ADODB_mysqli - - > - ErrorMsg()\n/var/www/html/mantisbt/admin/install.php: 431: - - - - db_error_msg()\n, referer: http://20.20.20.42/mantisbt/admin/install.php
40 [Tue Oct 23 10:11:29 2018] [error] [client 20.20.20.1] File does not exist: /var/www/html/mantisbt/css/admin, referer: http://20.20.20.42/mantisbt/admin/install.php

/var/www/html/mantisbt/admin/install.php
431 'Does administrative user have access to the database? ( ' . string_attribute( db_error_msg() ) . ' )'