I have install Project server 2010 on application server. SharePoint is already installed on same. Now when I am trying to create Project Web App site I am getting below error:

Failed to provision site PWATest with error: Microsoft.SharePoint.SPException: The security validation for this page is invalid. Click Back in your Web browser, refresh the page, and try your operation again. —> System.Runtime.InteropServices.COMException (0x8107058A): 0x8107058aThe security validation for this page is invalid. Click Back in your Web browser, refresh the page, and try your operation again.

I have followed below article to install Project Server 2010 http://epmcentral.com/articles/ps10/ps10installsteps.php

Please share your thoughts and useful links for the Issue. Thanks in Advance.