Surface Toolbox of 3D Slicer do not work in Windows

How to use surface toolbox in 3d slicer in Windows? why it keeps giving this error: C:\Users\AppData\Local\slicer.org\Slicer 5.6.2\bin\Python\slicer\util.py:2786: UserWarning: does not have observer
warn(“does not have observer”)
Can anyone please tell me if there is need for any installation or anything? if so, then how to do that?

I don’t think this error has anything to do with why Surface Toolbox does not work for you. Unfortunately this error appears no matter what, but it’s harmless.

Can you describe in detail how Surface Toolbox does not work? What you do exactly, what steps in what order, then what do you expect, and what happens instead?