I've got a simple solid aluminum structure mounted to a plate. The design is new and the geometry is subject to change. The structure supports a swinging pendulum used for shock testing. I excluded the arm from the assembly and put a load on the shaft holes to simulate the force from the pendulum. I have defined my contacts, applied a simple fixture to the bottom of the base plate to simulate it being mounted to a table or floor. The assembly will mesh but will not attempt to run. I get a warning saying that "one or more loads/contacts/fixtures are invalid". Yeah that really helps SW.
Check out the doc attached