Project Server 2013 Configuration Wizard Error

Hi Everyone,

I have installed SharePoint 2013 over Single Server with built in DB. Server uses Windows Server 2008 & SQL Server2008. SharePoint installed correctly and it is running well.

Now, I need to install Project Server 2013, so I installed its required updated, its prerequisites, then installed it. After installation, Configuration wizard started, but it failed with following error info:-

What is the reason of that error and how to solve this problem?

Thanks ,

Wa'el Mohsen