Just to be clear, you may not have to redefine the material definitions when copying analysis systems. There is no way to know how this occured without knowing the steps that lead to this. I frequently copy/duplicate analysis systems and have never encountered this issue with materials. I have however encountered issues where mechanical and workbench are out of sync with regard to what information they think is up to date, usually associated with geometry updates. This happens time to time, and as with all things FEA, the user should be vigilant as to what is going into the solver.n