Error when I do first migration in .NET Core 8

Question

I have a solution that contains three project.

1. EmployeeManagement.Database -- class library where the DbContext is defined
2. EmployeeManagement.Entities -- class library that contains all my entities
3. EmployeeManagement.WebAPI -- Web API project

I am trying to create a DbContext that inherits from IdentityDbContext, but I got this error when I try to use dotnet ef migrations add InitialMigration from my EmployeeManagement.WebAPI project.

ERROR:

An error occurred while accessing the Microsoft.Extensions.Hosting services. Continuing without the application service provider. Error: Some services are not able to be constructed (Error while validating the service descriptor 'ServiceType: Microsoft.AspNetCore.Identity.ISecurityStampValidator Lifetime: Scoped ImplementationType: Microsoft.AspNetCore.Identity.SecurityStampValidator1[EmployeeManagement.Entities.ApplicationUser]': Unable to resolve service for type 'System.TimeProvider' while attempting to activate 'Microsoft.AspNetCore.Identity.IdentityBuilderExtensions+PostConfigureSecurityStampValidatorOptions'.) (Error while validating the service descriptor 'ServiceType: Microsoft.AspNetCore.Identity.ITwoFactorSecurityStampValidator Lifetime: Scoped ImplementationType: Microsoft.AspNetCore.Identity.TwoFactorSecurityStampValidator1[EmployeeManagement.Entities.ApplicationUser]': Unable to resolve service for type 'System.TimeProvider' while attempting to activate 'Microsoft.AspNetCore.Identity.IdentityBuilderExtensions+PostConfigureSecurityStampValidatorOptions'.) (Error while validating the service descriptor 'ServiceType: Microsoft.Extensions.Options.IPostConfigureOptions1[Microsoft.AspNetCore.Identity.SecurityStampValidatorOptions] Lifetime: Singleton ImplementationType: Microsoft.AspNetCore.Identity.IdentityBuilderExtensions+PostConfigureSecurityStampValidatorOptions': Unable to resolve service for type 'System.TimeProvider' while attempting to activate 'Microsoft.AspNetCore.Identity.IdentityBuilderExtensions+PostConfigureSecurityStampValidatorOptions'.) (Error while validating the service descriptor 'ServiceType: Microsoft.AspNetCore.Identity.DataProtectorTokenProvider1[EmployeeManagement.Entities.ApplicationUser] Lifetime: Transient ImplementationType: Microsoft.AspNetCore.Identity.DataProtectorTokenProvider1[EmployeeManagement.Entities.ApplicationUser]': Unable to resolve service for type 'Microsoft.AspNetCore.DataProtection.IDataProtectionProvider' while attempting to activate 'Microsoft.AspNetCore.Identity.DataProtectorTokenProvider1[EmployeeManagement.Entities.ApplicationUser]'.)

No DbContext was found in assembly 'EmployeeManagement.WebAPI'. Ensure that you're using the correct assembly and that the type is neither abstract nor generic.

My DbContext:

public class ApplicationDbContext : IdentityDbContext<ApplicationUser>
{
    public ApplicationDbContext(DbContextOptions<ApplicationDbContext> options): base(options)
    {
    }

    public DbSet<ApplicationUser> ApplicationUsers { get; set; }
  
    protected override void OnModelCreating(ModelBuilder modelBuilder)
    {
    }
}

ApplicationUser class:

public class ApplicationUser : IdentityUser
{
}

program.cs:

using EmployeeManagement.Database;
using EmployeeManagement.Entities;
using Microsoft.AspNetCore.Identity;
using Microsoft.EntityFrameworkCore;

var builder = WebApplication.CreateBuilder(args);

// Add services to the container.

builder.Services.AddControllers();
// Learn more about configuring Swagger/OpenAPI at https://aka.ms/aspnetcore/swashbuckle
builder.Services.AddEndpointsApiExplorer();
builder.Services.AddSwaggerGen();

builder.Services.AddDbContext<ApplicationDbContext>(options =>
    options.UseSqlServer(builder.Configuration.GetConnectionString("DefaultConnection")));

builder.Services.AddAuthorization();
builder.Services.AddIdentityCore<ApplicationUser>()
    .AddEntityFrameworkStores<ApplicationDbContext>()
    .AddApiEndpoints();

var app = builder.Build();

// Configure the HTTP request pipeline.
if (app.Environment.IsDevelopment())
{
    app.UseSwagger();
    app.UseSwaggerUI();
}

app.MapIdentityApi<ApplicationUser>();

app.UseHttpsRedirection();
app.UseAuthorization();

app.MapControllers();

app.Run();

appsettings.json:

{
    "ConnectionStrings": {
        "DefaultConnection": "Server=localhost;Database=EmployeeManagementDb;Persist Security Info=True;User ID=PPPP;Password=PPPPPP;MultipleActiveResultSets=True;"
    },
    "Logging": {
        "LogLevel": {
            "Default": "Information",
            "Microsoft.AspNetCore": "Warning"
        }
    },
    "AllowedHosts": "*"
}

Answer 1

For me, I had a solution with following folder structure.

soln
  --> Data
  --> Service
  --> Model

To run migration in Data folder whereas startup class is set to Service, please follow below Package Manager Console Commands to run one-by-one.

Add Migration Command

Add-Migration {Migration_Name} -Project Data -StartupProject Service

NOTE: Replace {Migration_Name} with new Migration file Name

Update Database Command

Update-Database -Project Data -StartupProject Service

Once all required packages installed and set your WebAPI project as startup project, this should work.