Problem facing to Install PKP Harvester

I have installed Ubuntu 16.04 Desktop Version, Mysql and PHP. I have checked that default index.php page is appearing at localhost. However, I have un-tar ohs-2.3.2.tar.gz under /var/www/html. Name of the directory is ohs. Set the permission as per requirements. However, http://localhost/ohs or IP/ohs is showing, page is not working. It is loading index.php of ohs, however, it is loading locally created php file like http://localhost/ohs/12.php.

I need help

Can you clarify your last sentence?

It is loading index.php of ohs, however, it is loading locally created php file like ‘http://localhost/ohs/12.php’.

Did you mean it is not loading the OHS index.php, but is loading a testing file of 12.php?

What error messages do you see on the screen, or in the error log?

yes, it is not index.php of OHS. Test page is OK.

Showing just white page. No error message

See the FAQ I linked earlier. There will be details on the cause of the whitescreen in your server’s error log: