dotnet/efcore · error · OperationException

You cannot add a migration with the name 'Migration'.

Error message

You cannot add a migration with the name 'Migration'.

What it means

MigrationsScaffolder.ScaffoldMigration forbids a migration literally named 'Migration' (case-insensitive) because the generated migration class derives from the base 'Migration' class; naming it 'Migration' would create a circular base-class dependency (class Migration : global::Microsoft.EntityFrameworkCore.Migrations.Migration is illegal). The guard is a simple string.Equals against 'migration' with OrdinalIgnoreCase.

Solutions

1. Pick any other name, e.g. 'InitialCreate', 'AddOrders', 'v1'.

Example fix

# before
dotnet ef migrations add migration
# after
dotnet ef migrations add InitialCreate

if (string.Equals(migrationName, "migration", StringComparison.OrdinalIgnoreCase))
{
    throw new ArgumentException("Migration name cannot be 'Migration'.", nameof(migrationName));
}

try { scaffolder.ScaffoldMigration(name, rootNs, subNs, language, dryRun); }
catch (OperationException ex) when (ex.Message.Contains("with the name 'Migration'"))
{ /* pick a different name */ }

When it happens

Trigger: Calling ScaffoldMigration with migrationName == "Migration" (any case). The check fires before duplicate-name and namespace handling.

Common situations: User types 'dotnet ef migrations add migration'; a tool/scaffold defaults the name to the noun 'Migration'; copy-paste of a generic template.

Related errors

• The name you have chosen for the migration
• The project language
• A migration name must be specified.
• A seed entity for entity type
• A seed entity for entity type

AI-assisted analysis of dotnet/efcore@3a2006ef56 (2026-08-11). Data as JSON: /api/errors/5fb65d4c7a4cfe08. Report an issue: GitHub.

Appendix: source

Thrown at src/EFCore.Design/Migrations/Design/MigrationsScaffolder.cs:75

    ///     namespace generation, just use sub-namespace as is.
    /// </param>
    /// <param name="subNamespace">
    ///     The migration's sub-namespace. Note: the root-namespace and
    ///     the sub-namespace should not both be empty.
    /// </param>
    /// <param name="language">The project's language.</param>
    /// <param name="dryRun">If <see langword="true" />, then nothing is actually written to disk.</param>
    /// <returns>The scaffolded migration.</returns>
    public virtual ScaffoldedMigration ScaffoldMigration(
        string migrationName,
        string? rootNamespace,
        string? subNamespace = null,
        string? language = null,
        bool dryRun = false)
    {
        if (string.Equals(migrationName, "migration", StringComparison.OrdinalIgnoreCase))
        {
            throw new OperationException(DesignStrings.CircularBaseClassDependency);
        }

        if (Dependencies.MigrationsAssembly.FindMigrationId(migrationName) != null)
        {
            throw new OperationException(DesignStrings.DuplicateMigrationName(migrationName));
        }

        var overrideNamespace = rootNamespace == null;
        var subNamespaceDefaulted = false;
        if (string.IsNullOrEmpty(subNamespace) && !overrideNamespace)
        {
            subNamespaceDefaulted = true;
            subNamespace = "Migrations";
        }

        var (key, typeInfo) = Dependencies.MigrationsAssembly.Migrations.LastOrDefault();

        var migrationNamespace =

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