The 3D NSEM example does not work

Hello!
The plot_fwd_nsem_MTTipper3D example does not work,what is the reason?
Thank you very much for your answer!

Hello Xiehaijun, could you provide more detail? Was there an error message?

Hello jkutt85
This code doesn’t report errors and it doesn’t stop running。
It gets stuck in this line of code:

data = NSEM.Data(survey=survey, dobs=problem.dpred())

According to my analysis, the problem is with this function-dpred(), but I don’t know how to modify it.
Thank you very much for your reply!