Issue
You have setup all your formulae & they have been working in the past but no longer work at all.
Resolution
Check that the sandboxed Asyncronous Windows service is running. You can check this by going to the server that you have installed Microsoft Dynamics 365 2011 on & checking its list of Windows services that the one named "Microsoft Dynamics 365 Sandbox Processing Service" is started. If it is not started then start the service.