The entity type 'Microsoft.AspNetCore.Mvc.Rendering.SelectListGroup' requires a primary key to be defined [duplicate]

Answer 1

In order to fix this, simply put

[NotMapped]

above the SelectList property within the model .cs file:

[NotMapped]
public SelectList SiteList { get; set; }

This prevents EntityFramework from mapping the list to the model. Since it's not part of the model database, it doesn't require a primary key.