我已經(jīng)從https://aspnetboilerplate.com/Templates下載了Asp.Net MVC 5.x單頁Web應(yīng)用程序。我正在使用MySQL，并按照鏈接https://aspnetboilerplate.com/Pages/Documents/EF-MySql-Integration中提到的步驟進(jìn)行操作。但是，當(dāng)我運(yùn)行Add-Migration命令時，它給出了錯誤。MyCompany.MyProject.Web \ Web.Config：<add name="Default" connectionString="Server=127.0.0.1;port=3306;Database=SparTestDb;uid=root;password=root" providerName="MySql.Data.MySqlClient"/>MyCompany.MyProject.EntityFramework \ Migrations \ Configuration.cspublic Configuration(){    AutomaticMigrationsEnabled = false;    ContextKey = "Spar";    SetSqlGenerator("MySql.Data.MySqlClient", new MySql.Data.Entity.MySqlMigrationSqlGenerator());}錯誤：PM> Add-Migration“ AbpZero_Initial” System.NullReferenceException：對象引用未設(shè)置為對象的實(shí)例。在System.Data.Entity.Core.Common.DbProviderServices.GetProviderManifestToken（DbConnection連接）在MySql.Data.MySqlClient.MySqlProviderServices.GetDbProviderManifestToken（DbConnection連接） ）在System.Data.Entity.Infrastructure.DefaultManifestTokenResolver。<> c__DisplayClass1.b__0（Tuple 3  k)    at  System.Collections.Concurrent.ConcurrentDictionary2.GetOrAdd（TKey鍵，F(xiàn)unc 2 valueFactory)    at  System.Data.Entity.Infrastructure.DefaultManifestTokenResolver.ResolveManifestToken(DbConnection  connection)    at  System.Data.Entity.Utilities.DbConnectionExtensions.GetProviderInfo(DbConnection  connection, DbProviderManifest& providerManifest)    at  System.Data.Entity.DbModelBuilder.Build(DbConnection  providerConnection)    at  System.Data.Entity.Internal.LazyInternalContext.CreateModel(LazyInternalContext  internalContext)    at  System.Data.Entity.Internal.RetryLazy2.GetValue（TInput輸入）在System.Data.Entity.Internal.LazyInternalContext.InitializeContext（）