...
In order to prevent security risks, this step needs to proceed right after the installation is completed without any problem. Please go to folder /PF.Base/file/log/ and remove the installation.log file there. Since version 4.6.1 build 4, this file will be removed automatically if the installation is completed properly.
...
Make your phpFox site more secure
This is SHOULD HAVE step to make your site more secure but it requires technical knowledge about the server system. Therefore, please feel free to contact your system admin or hosting provider for help if you are not familiar with server stuff.
You should grant permissions of files and folders to "web user" account as below:
...