Resolving 'InvalidOperationException' when using Entity Framework Core with Lazy Loading in .NET 6
I'm integrating two systems and I'm having a hard time understanding I'm encountering an `InvalidOperationException` when trying to access a navigation property in my Entity Framework Core (EF Core) model that uses lazy loading... I'm using .NET 6 and EF Core 6. My setup includes a simple model with a `Blog` class and a related `Post` class, where a blog can have multiple posts. I've configured lazy loading by installing the `Microsoft.EntityFrameworkCore.Proxies` package and calling `UseLazyLoadingProxies()` in my `DbContext` configuration. Here’s a simplified version of my model classes: ```csharp public class Blog { public int BlogId { get; set; } public string Url { get; set; } public virtual ICollection<Post> Posts { get; set; } } public class Post { public int PostId { get; set; } public string Title { get; set; } public int BlogId { get; set; } public virtual Blog Blog { get; set; } } ``` In my `DbContext`, I've configured it like this: ```csharp public class BloggingContext : DbContext { public DbSet<Blog> Blogs { get; set; } public DbSet<Post> Posts { get; set; } protected override void OnConfiguring(DbContextOptionsBuilder optionsBuilder) { optionsBuilder.UseSqlServer("YourConnectionString").UseLazyLoadingProxies(); } } ``` When I try to access the `Posts` property of a `Blog` instance like this: ```csharp using (var context = new BloggingContext()) { var blog = context.Blogs.FirstOrDefault(b => b.BlogId == 1); var posts = blog.Posts.ToList(); // Throws InvalidOperationException } ``` I’m getting the following exception: ``` System.InvalidOperationException: The navigation property 'Posts' is not loaded ``` I've verified that the relevant blog with `BlogId` 1 exists in the database, and I've also checked that lazy loading is properly configured. I’ve tried explicitly loading the navigation property with `.Include(b => b.Posts)` and that works, but I want to use lazy loading for cleaner code. I've also checked the project file to ensure that the correct version of EF Core is being referenced. What could be causing this issue with lazy loading? Are there any specific configurations or best practices I might be missing? Any help would be greatly appreciated! Is there a better approach? For context: I'm using Csharp on Ubuntu 20.04.