Issue in Migration DotNet Core during initial start.

[Aditya-Agarwal01]

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When we create new project for Dot Net Core having Identity Framework for User, Role etc now we have try to do migration for these but got stuck and giving this error during add-migration comment.

An error occurred while accessing the Microsoft.Extensions.Hosting services. Continuing without the application service provider. Error: Method not found: 'System.Collections.Generic.IEnumerable1<Microsoft.EntityFrameworkCore.Metadata.IMutableProperty> Microsoft.EntityFrameworkCore.Metadata.IMutableEntityType.GetProperties()'. Unable to create a 'DbContext' of type 'AuthDbContext'. The exception 'Method not found: 'System.Collections.Generic.IEnumerable1<Microsoft.EntityFrameworkCore.Metadata.IMutableProperty> Microsoft.EntityFrameworkCore.Metadata.IMutableEntityType.GetProperties()'.' was thrown while attempting to create an instance. For the different patterns supported at design time, see https://go.microsoft.com/fwlink/?linkid=851728

DbContext :- `public class AuthDbContext : IdentityDbContext<User, Role, string>
{

private readonly IEncryptionProvider _encryptionProvider;
private const string encryptionProvider = "JaNdRfUserjd89#5*6Xn2r5usErw8x/A";
private IMapper _mapper;

/// <summary>
/// Default DbContext contructor used for Dependency Injection by DbContext Pooling
/// </summary>
/// <param name="options"></param>
public AuthDbContext(DbContextOptions<AuthDbContext> options) : base(options)
{
    //Provider key should be of 32 characters to support 256 bits encryption
    this._encryptionProvider = new GenerateEncryptionProvider(encryptionProvider);
}

/// <summary>
/// Sets the AutoMapper instance for the DbContext.
/// </summary>
/// <param name="mapper">The AutoMapper instance to be set.</param>
/// <returns>The current instance of AuthDbContext with the AutoMapper set.</returns>
public AuthDbContext SetAutoMapper(IMapper mapper)
{
    _mapper = mapper;
    return this;
}

#pragma warning disable 1591

public DbSet<RoleGroup> UserGroups { get; set; }
public DbSet<AuthConfig> AuthConfigs { get; set; }
public DbSet<UserAccountConfig> UserAccountConfigs { get; set; }

#pragma warning restore 1591

/// <summary>
/// Method for configuring Model classes
/// </summary>
/// <param name="builder">An instance of ModelBuilder class</param>
protected override void OnModelCreating(ModelBuilder builder)
{

    
    //This is for Column/ Property/ Field Encryption Decryption
    builder.UseEncryption(this._encryptionProvider);
    //***************************
    base.OnModelCreating(builder);
    IdentityModelsConfiguration.Configure(builder);

    MasterSeeder.Seed(builder);

}

/// <summary>
/// Method to configure SQL Server related properties
/// </summary>
/// <param name="optionsBuilder">An instance of DbContextOptionsBuilder</param>
protected override void OnConfiguring(DbContextOptionsBuilder optionsBuilder)
{
    base.OnConfiguring(optionsBuilder);
}

}`
In Program.cs we describe their AddDbContextPool for configuration.
Can anyone suggest what mistake i done in the code.

[GabrieleTronchin]

Hi @Aditya-Agarwal01,

I suspect that within one of the following classes: RoleGroup, AuthConfig, or UserAccountConfig, there may be one or more properties declared as IEnumerable, which results in a read-only collection. To resolve this, try changing the property type to List, which allows modification.

Let me know if this helps!