I am running a simple static study to assess the thermal expansion of a part, however the study always stops and I keep getting an error: "Thermal expansion coefficient (Alphx) is not defined for element 1". I have run the same simulation with the same material on a different part and it worked without error, so I assume that the geometry of the part is causing the problem. Can anyone help me identify what I need to look for to solve this issue?

I am using SW 2015 SP 5.0.