I tried the Nop Plugin Multi Tenant latest version that support Nopcommerce 3.8 and this is what I found.
After I run the database script file, and copy/replace the folder /Application and /bin; when sign in as admin and access the backend, there is popup error twice. Then when continue click on the "Add New" in "Mapping Users to Stores", the error page shows (not popup) "We are encounting error..."
I am using clean Nopcommerce without any additional modification, just install and apply this multi tenant.
Ok, I it's almost work now, using web no source there is no error anymore. But the admin menu "Mapping Users to Stores" is missing, there is no this menu displayed.