System.MissingMethodException: Method not found: 'Void Microsoft.EntityFrameworkCore.Scaffolding.Metadata.DatabaseTable..ctor(Microsoft.EntityFrameworkCore.Scaffolding.Metadata.DatabaseModel, System.String)'.

Below is the complete stack trace of the error I receive when using following scaffold command. What could be wrong?

I am using Npgsql Postgres code, changed for my database as far as internal SQLs are concerned, as such no change in logic flow. Changed GetTables() method code is pasted below for reference, it calls “DatabaseTable()” which results into “System.MissingMethodException” exception.

…\Scaffolding\Internal\NpgsqlDatabaseModelFactory.cs

    /// <summary>
    /// Queries the database for defined tables and registers them with the model.
    /// </summary>
    static IEnumerable<DatabaseTable> GetTables(
        IfxConnection connection,
        DatabaseModel databaseModel,
        IDiagnosticsLogger<DbLoggerCategory.Scaffolding> logger)
    {
        var commandText = @"
        SELECT
           owner, tabname
        FROM
           informix.sysmaster:systables
        WHERE
           tabid > 99;";

        var tables = new List<DatabaseTable>();

        var command = new IfxCommand(commandText, connection);
        using (var reader = command.ExecuteReader())
        {
            while (reader.Read())
            {
                var schema = reader.GetValueOrDefault<string>("owner");
                var name = reader.GetString("tabname");

                var table = new DatabaseTable(databaseModel, name)
                {
                    Schema = schema,
                };

                tables.Add(table);
            }
        }

        GetColumns(connection, tables, logger);
        GetConstraints(connection, tables, out var constraintIndexes, logger);
        GetIndexes(connection, tables, constraintIndexes, logger);
        return tables;
    }

D:\shesh\EntityFrameworkCore\scaffold>dotnet ef dbcontext scaffold “Database=sheshefcoredb1; server=lo_informix1410;UID=informix; PWD=xxx” Informix.EntityFramework.Core -o Models --project MyApp.csproj -v Using project ‘MyApp.csproj’. Using startup project ‘D:\shesh\EntityFrameworkCore\scaffold\MyApp.csproj’. Writing ‘obj\MyApp.csproj.EntityFrameworkCore.targets’… dotnet msbuild /target:GetEFProjectMetadata /property:EFProjectMetadataFile=C:\Users\sheshnarayan.a\AppData\Local\Temp\tmpE5DF.tmp /verbosity:quiet /nologo MyApp.csproj Writing ‘D:\shesh\EntityFrameworkCore\scaffold\obj\MyApp.csproj.EntityFrameworkCore.targets’… dotnet msbuild /target:GetEFProjectMetadata /property:EFProjectMetadataFile=C:\Users\sheshnarayan.a\AppData\Local\Temp\tmpEA65.tmp /verbosity:quiet /nologo D:\shesh\EntityFrameworkCore\scaffold\MyApp.csproj Build started… dotnet build D:\shesh\EntityFrameworkCore\scaffold\MyApp.csproj /verbosity:quiet /nologo

Build succeeded. 0 Warning(s) 0 Error(s)

Time Elapsed 00:00:01.46 Build succeeded. dotnet exec --depsfile D:\shesh\EntityFrameworkCore\scaffold\bin\x64\Debug\netcoreapp3.1\MyApp.deps.json --additionalprobingpath C:\Users\sheshnarayan.a.nuget\packages --additionalprobingpath “C:\Program Files\dotnet\sdk\NuGetFallbackFolder” --runtimeconfig D:\shesh\EntityFrameworkCore\scaffold\bin\x64\Debug\netcoreapp3.1\MyApp.runtimeconfig.json C:\Users\sheshnarayan.a.dotnet\tools.store\dotnet-ef\3.1.5\dotnet-ef\3.1.5\tools\netcoreapp3.1\any\tools\netcoreapp2.0\any\ef.dll dbcontext scaffold “Database=sheshefcoredb1; server=lo_informix1410;UID=informix; PWD=xxx” Informix.EntityFramework.Core -o Models --assembly D:\shesh\EntityFrameworkCore\scaffold\bin\x64\Debug\netcoreapp3.1\MyApp.dll --startup-assembly D:\shesh\EntityFrameworkCore\scaffold\bin\x64\Debug\netcoreapp3.1\MyApp.dll --project-dir D:\shesh\EntityFrameworkCore\scaffold\ –language C# --working-dir D:\shesh\EntityFrameworkCore\scaffold --verbose --root-namespace MyApp Using assembly ‘MyApp’. Using startup assembly ‘MyApp’. Using application base ‘D:\shesh\EntityFrameworkCore\scaffold\bin\x64\Debug\netcoreapp3.1’. Using working directory ‘D:\shesh\EntityFrameworkCore\scaffold’. Using root namespace ‘MyApp’. Using project directory 'D:\shesh\EntityFrameworkCore\scaffold'. The EF Core tools version ‘3.1.5’ is older than that of the runtime ‘5.0.0-preview.5.20278.2’. Update the tools for the latest features and bug fixes. Finding design-time services for provider ‘Informix.EntityFramework.Core’… Using design-time services from provider ‘Informix.EntityFramework.Core’. Finding design-time services referenced by assembly ‘MyApp’. No referenced design-time services were found. Finding IDesignTimeServices implementations in assembly ‘MyApp’… No design-time services were found. System.MissingMethodException: Method not found: ‘Void Microsoft.EntityFrameworkCore.Scaffolding.Metadata.DatabaseTable…ctor(Microsoft.EntityFrameworkCore.Scaffolding.Metadata.DatabaseModel, System.String)’. at Informix.EntityFramework.Core.Scaffolding.Internal.NpgsqlDatabaseModelFactory.GetTables(IfxConnection connection, DatabaseModel databaseModel, IDiagnosticsLogger1 logger) at Informix.EntityFramework.Core.Scaffolding.Internal.NpgsqlDatabaseModelFactory.Create(DbConnection dbConnection, DatabaseModelFactoryOptions options) in D:\shesh\EntityFrameworkCore\efcore.pg-dev-ifmx-old\src\EFCore.Informix\Scaffolding\Internal\NpgsqlDatabaseModelFactory.cs:line 124 at Informix.EntityFramework.Core.Scaffolding.Internal.NpgsqlDatabaseModelFactory.Create(String connectionString, DatabaseModelFactoryOptions options) in D:\shesh\EntityFrameworkCore\efcore.pg-dev-ifmx-old\src\EFCore.Informix\Scaffolding\Internal\NpgsqlDatabaseModelFactory.cs:line 90 at Microsoft.EntityFrameworkCore.Scaffolding.Internal.ReverseEngineerScaffolder.ScaffoldModel(String connectionString, DatabaseModelFactoryOptions databaseOptions, ModelReverseEngineerOptions modelOptions, ModelCodeGenerationOptions codeOptions) at Microsoft.EntityFrameworkCore.Design.Internal.DatabaseOperations.ScaffoldContext(String provider, String connectionString, String outputDir, String outputContextDir, String dbContextClassName, IEnumerable1 schemas, IEnumerable1 tables, String modelNamespace, String contextNamespace, Boolean useDataAnnotations, Boolean overwriteFiles, Boolean useDatabaseNames) at Microsoft.EntityFrameworkCore.Design.OperationExecutor.ScaffoldContextImpl(String provider, String connectionString, String outputDir, String outputDbContextDir, String dbContextClassName, IEnumerable1 schemaFilters, IEnumerable1 tableFilters, String modelNamespace, String contextNamespace, Boolean useDataAnnotations, Boolean overwriteFiles, Boolean useDatabaseNames) at Microsoft.EntityFrameworkCore.Design.OperationExecutor.ScaffoldContext.<>c__DisplayClass0_0.<.ctor>b__0() at Microsoft.EntityFrameworkCore.Design.OperationExecutor.OperationBase.<>c__DisplayClass3_01.<Execute>b__0() at Microsoft.EntityFrameworkCore.Design.OperationExecutor.OperationBase.Execute(Action action) Method not found: ‘Void Microsoft.EntityFrameworkCore.Scaffolding.Metadata.DatabaseTable…ctor(Microsoft.EntityFrameworkCore.Scaffolding.Metadata.DatabaseModel, System.String)’.

D:\shesh\EntityFrameworkCore\scaffold>

[ErikEJ]

You should never base a new provider on EF Core previews - ask me how I know 😭

[smitpatel]

You have mixed versions of packages.