I am trying to work with fasteners in Pro/Mechanica. The issue I am having is the stress concentrations resulting in the load passing through the fastener. I would like to change the head diameter of the bolt, to the head diameter of the actual bolt, but I get errors when I try to change it. The only way that I have found to specify the diameter of the head is to select "include preload" and change it there. You are required to put a preload in, which I do not want to do, and any value I put in there gives me an error when I try to run the analysis. I get the message "The fastener is invalid. Please redefine the fastener." (I have 20 fasteners, so that message is not very descriptive, but that