EPM2010 – Error ‘Project Web App cannot connect to Project Sever’ (After Upgrade)

I recently came across this error message after upgrading from 2003 > 2007 > 2010.

Note: SP/PS2010 version is at June 2012 CU (v6123) patch level.

Resolution;

1. Ensure Project Server Service is running. Check within SP Central Admin.
2. Run the SharePoint configuration wizard to ensure all the DBs in the farm are upgraded correctly and are at the same version/patch level.
3. Re-boot the server(s)

Voila!! Your system will up and running.