I thought I would post this little gem so I don’t forget it. Hopefully it will be of use to someone else as well. In the last couple of weeks a few people have told me about issues they encountered running Project Server 2010 workflows on a farm where the web front-end service has been deactivated. Deactivating the service can make sense if you are configuring the farm for improved performance by removing the need to listen to and render pages, or when trying to reduce the attack surface (although this is a lesser concern).