Unable to install 7.2.7 on CentOS Linux release 7.3 (version 7.1.5 works fine)

My engineer has tried a fresh installation and the result is as follows.

1. After unzip, we get the configuration page.
After entering the new database details, we get the screen shown below:


The Webserver log is here


Note :- Even though it is a NEW installation, still it is referring as an "upgrade". Is there a clue in this?

The Database does not show any tables, as can be seen from the following:

mysql -uprojeqtor727 -pprojeqtor727 projeqtor727
Welcome to the MariaDB monitor. Commands end with ; or \g.
Your MariaDB connection id is 795134
Server version: 5.5.52-MariaDB MariaDB Server

MariaDB [projeqtor727]> show tables;
Empty set (0.00 sec)

MariaDB [projeqtor727]>

**********
My engineer tried to install a "pure vanilla" version of the V7.3.1 RC, but he gets the same result.

oops. Wrong screenshot! My engineer had tried to log in as Admin.

Did you find anything in the log?

My engineer says that there is no other error from Apapche as the error is not from Web server side.

Nevertheless, if you still feel that there is another error log file, please guide me with likely location for this error log file.
Thanks in advance!