Several stack ups for an inductor sims

Hello

I am MOM simulating an inductor with several stack up files. Once I simulate the inductor with one stack-up, I want to compare the same inductor with a different stack-up. In this case, when I pre-compute the 2nd substrate, the momentum says there is already substrate function exist and then quits.
I guess I have to delete the computed substrate function on the 1st stack-up to compute the 2nd stack-up.
Can you tell where I can find this substrate function?

Are there other ways to bypass this issue?

Thanks a lot.