实体框架6加载System.Data.SqlClient失败

我最近在服务器上部署了应用程序，我得到了实体框架6的问题。它就这样失败了。在部署/配置更改后的第一次尝试，我得到这个错误:

[ConfigurationErrorsException: The 'DbProviderFactories' section can only appear once per config file.]
   System.Configuration.BaseConfigurationRecord.EvaluateOne(String[] keys, SectionInput input, Boolean isTrusted, FactoryRecord factoryRecord, SectionRecord sectionRecord, Object parentResult) +834506
   System.Configuration.BaseConfigurationRecord.Evaluate(FactoryRecord factoryRecord, SectionRecord sectionRecord, Object parentResult, Boolean getLkg, Boolean getRuntimeObject, Object& result, Object& resultRuntimeObject) +836240
   System.Configuration.BaseConfigurationRecord.GetSectionRecursive(String configKey, Boolean getLkg, Boolean checkPermission, Boolean getRuntimeObject, Boolean requestIsHere, Object& result, Object& resultRuntimeObject) +853722
   System.Configuration.BaseConfigurationRecord.GetSectionRecursive(String configKey, Boolean getLkg, Boolean checkPermission, Boolean getRuntimeObject, Boolean requestIsHere, Object& result, Object& resultRuntimeObject) +853722
   System.Configuration.BaseConfigurationRecord.GetSectionRecursive(String configKey, Boolean getLkg, Boolean checkPermission, Boolean getRuntimeObject, Boolean requestIsHere, Object& result, Object& resultRuntimeObject) +853722
   System.Configuration.BaseConfigurationRecord.GetSectionRecursive(String configKey, Boolean getLkg, Boolean checkPermission, Boolean getRuntimeObject, Boolean requestIsHere, Object& result, Object& resultRuntimeObject) +853722
   System.Configuration.BaseConfigurationRecord.GetSection(String configKey) +69
   System.Configuration.ConfigurationManager.GetSection(String sectionName) +140
   System.Configuration.PrivilegedConfigurationManager.GetSection(String sectionName) +43
   System.Data.Common.DbProviderFactories.Initialize() +218
   System.Data.Common.DbProviderFactories.GetProviderTable() +9
   System.Data.Entity.Infrastructure.DependencyResolution.DefaultProviderFactoryResolver.GetService(Type type, Object key, Func`3 handleFailedLookup) +146
   System.Collections.Concurrent.ConcurrentDictionary`2.GetOrAdd(TKey key, Func`2 valueFactory) +83
   System.Data.Entity.Infrastructure.DependencyResolution.CachingDependencyResolver.GetService(Type type, Object key) +179
   System.Linq.WhereSelectArrayIterator`2.MoveNext() +82
   System.Linq.Enumerable.FirstOrDefault(IEnumerable`1 source, Func`2 predicate) +215
   System.Linq.WhereSelectArrayIterator`2.MoveNext() +82
   System.Linq.Enumerable.FirstOrDefault(IEnumerable`1 source, Func`2 predicate) +215
   System.Data.Entity.Infrastructure.DependencyResolution.CompositeResolver`2.GetService(Type type, Object key) +71
   System.Data.Entity.Infrastructure.DependencyResolution.DbDependencyResolverExtensions.GetService(IDbDependencyResolver resolver, Object key) +84
   System.Data.Entity.Core.EntityClient.EntityConnection.ChangeConnectionString(String newConnectionString) +691
   System.Data.Entity.Core.EntityClient.EntityConnection..ctor(String connectionString) +141
   System.Data.Entity.Internal.LazyInternalConnection.TryInitializeFromAppConfig(String name, AppConfig config) +186
   System.Data.Entity.Internal.LazyInternalConnection.Initialize() +95
   System.Data.Entity.Internal.LazyInternalConnection.CreateObjectContextFromConnectionModel() +16
   System.Data.Entity.Internal.LazyInternalContext.InitializeContext() +408
   System.Data.Entity.Internal.InternalContext.GetEntitySetAndBaseTypeForType(Type entityType) +26
   System.Data.Entity.Internal.Linq.InternalSet`1.Initialize() +72
   System.Data.Entity.Internal.Linq.InternalSet`1.get_InternalContext() +21
   System.Data.Entity.Infrastructure.DbQuery`1.System.Linq.IQueryable.get_Provider() +68
   System.Linq.Queryable.FirstOrDefault(IQueryable`1 source, Expression`1 predicate) +85
   MobileDeviceDB.Controllers.AuthController.ShowIndex(LoginModel data) +1060
   lambda_method(Closure , ControllerBase , Object[] ) +79
   System.Web.Mvc.ReflectedActionDescriptor.Execute(ControllerContext controllerContext, IDictionary`2 parameters) +261
   System.Web.Mvc.ControllerActionInvoker.InvokeActionMethod(ControllerContext controllerContext, ActionDescriptor actionDescriptor, IDictionary`2 parameters) +39
   System.Web.Mvc.Async.<>c__DisplayClass42.<BeginInvokeSynchronousActionMethod>b__41() +34
   System.Web.Mvc.Async.<>c__DisplayClass39.<BeginInvokeActionMethodWithFilters>b__33() +124
   System.Web.Mvc.Async.<>c__DisplayClass4f.<InvokeActionMethodFilterAsynchronously>b__49() +839035
   System.Web.Mvc.Async.<>c__DisplayClass37.<BeginInvokeActionMethodWithFilters>b__36(IAsyncResult asyncResult) +15
   System.Web.Mvc.Async.<>c__DisplayClass2a.<BeginInvokeAction>b__20() +33
   System.Web.Mvc.Async.<>c__DisplayClass25.<BeginInvokeAction>b__22(IAsyncResult asyncResult) +839620
   System.Web.Mvc.<>c__DisplayClass1d.<BeginExecuteCore>b__18(IAsyncResult asyncResult) +28
   System.Web.Mvc.Async.<>c__DisplayClass4.<MakeVoidDelegate>b__3(IAsyncResult ar) +15
   System.Web.Mvc.Controller.EndExecuteCore(IAsyncResult asyncResult) +65
   System.Web.Mvc.Async.<>c__DisplayClass4.<MakeVoidDelegate>b__3(IAsyncResult ar) +15
   System.Web.Mvc.Controller.EndExecute(IAsyncResult asyncResult) +51
   System.Web.Mvc.<>c__DisplayClass8.<BeginProcessRequest>b__3(IAsyncResult asyncResult) +42
   System.Web.Mvc.Async.<>c__DisplayClass4.<MakeVoidDelegate>b__3(IAsyncResult ar) +15
   System.Web.Mvc.MvcHandler.EndProcessRequest(IAsyncResult asyncResult) +51
   System.Web.CallHandlerExecutionStep.System.Web.HttpApplication.IExecutionStep.Execute() +606
   System.Web.HttpApplication.ExecuteStep(IExecutionStep step, Boolean& completedSynchronously) +288

刷新后，我得到了这个异常:

[ArgumentException: Unable to find the requested .Net Framework Data Provider.  It may not be installed.]
   System.Data.Entity.Infrastructure.DependencyResolution.DefaultProviderFactoryResolver.GetService(Type type, Object key, Func`3 handleFailedLookup) +282
[ArgumentException: The ADO.NET provider with invariant name 'System.Data.SqlClien' is either not registered in the machine or application config file, or could not be loaded. See the inner exception for details.]
   System.Data.Entity.Infrastructure.DependencyResolution.DefaultProviderFactoryResolver.<GetService>b__0(ArgumentException e, String n) +58
   System.Data.Entity.Infrastructure.DependencyResolution.DefaultProviderFactoryResolver.GetService(Type type, Object key, Func`3 handleFailedLookup) +414
   System.Collections.Concurrent.ConcurrentDictionary`2.GetOrAdd(TKey key, Func`2 valueFactory) +83
   System.Data.Entity.Infrastructure.DependencyResolution.CachingDependencyResolver.GetService(Type type, Object key) +179
   System.Linq.WhereSelectArrayIterator`2.MoveNext() +82
   System.Linq.Enumerable.FirstOrDefault(IEnumerable`1 source, Func`2 predicate) +215
   System.Linq.WhereSelectArrayIterator`2.MoveNext() +82
   System.Linq.Enumerable.FirstOrDefault(IEnumerable`1 source, Func`2 predicate) +215
   System.Data.Entity.Infrastructure.DependencyResolution.CompositeResolver`2.GetService(Type type, Object key) +71
   System.Data.Entity.Infrastructure.DependencyResolution.DbDependencyResolverExtensions.GetService(IDbDependencyResolver resolver, Object key) +84
   System.Data.Entity.Core.EntityClient.EntityConnection.ChangeConnectionString(String newConnectionString) +691
   System.Data.Entity.Core.EntityClient.EntityConnection..ctor(String connectionString) +141
   System.Data.Entity.Internal.LazyInternalConnection.TryInitializeFromAppConfig(String name, AppConfig config) +186
   System.Data.Entity.Internal.LazyInternalConnection.Initialize() +95
   System.Data.Entity.Internal.LazyInternalConnection.CreateObjectContextFromConnectionModel() +16
   System.Data.Entity.Internal.LazyInternalContext.InitializeContext() +408
   System.Data.Entity.Internal.InternalContext.GetEntitySetAndBaseTypeForType(Type entityType) +26
   System.Data.Entity.Internal.Linq.InternalSet`1.Initialize() +72
   System.Data.Entity.Internal.Linq.InternalSet`1.get_InternalContext() +21
   System.Data.Entity.Infrastructure.DbQuery`1.System.Linq.IQueryable.get_Provider() +68
   System.Linq.Queryable.FirstOrDefault(IQueryable`1 source, Expression`1 predicate) +85
   MobileDeviceDB.Controllers.AuthController.ShowIndex(LoginModel data) +1060
   lambda_method(Closure , ControllerBase , Object[] ) +79
   System.Web.Mvc.ReflectedActionDescriptor.Execute(ControllerContext controllerContext, IDictionary`2 parameters) +261
   System.Web.Mvc.ControllerActionInvoker.InvokeActionMethod(ControllerContext controllerContext, ActionDescriptor actionDescriptor, IDictionary`2 parameters) +39
   System.Web.Mvc.Async.<>c__DisplayClass42.<BeginInvokeSynchronousActionMethod>b__41() +34
   System.Web.Mvc.Async.<>c__DisplayClass39.<BeginInvokeActionMethodWithFilters>b__33() +124
   System.Web.Mvc.Async.<>c__DisplayClass4f.<InvokeActionMethodFilterAsynchronously>b__49() +839035
   System.Web.Mvc.Async.<>c__DisplayClass37.<BeginInvokeActionMethodWithFilters>b__36(IAsyncResult asyncResult) +15
   System.Web.Mvc.Async.<>c__DisplayClass2a.<BeginInvokeAction>b__20() +33
   System.Web.Mvc.Async.<>c__DisplayClass25.<BeginInvokeAction>b__22(IAsyncResult asyncResult) +839620
   System.Web.Mvc.<>c__DisplayClass1d.<BeginExecuteCore>b__18(IAsyncResult asyncResult) +28
   System.Web.Mvc.Async.<>c__DisplayClass4.<MakeVoidDelegate>b__3(IAsyncResult ar) +15
   System.Web.Mvc.Controller.EndExecuteCore(IAsyncResult asyncResult) +65
   System.Web.Mvc.Async.<>c__DisplayClass4.<MakeVoidDelegate>b__3(IAsyncResult ar) +15
   System.Web.Mvc.Controller.EndExecute(IAsyncResult asyncResult) +51
   System.Web.Mvc.<>c__DisplayClass8.<BeginProcessRequest>b__3(IAsyncResult asyncResult) +42
   System.Web.Mvc.Async.<>c__DisplayClass4.<MakeVoidDelegate>b__3(IAsyncResult ar) +15
   System.Web.Mvc.MvcHandler.EndProcessRequest(IAsyncResult asyncResult) +51
   System.Web.CallHandlerExecutionStep.System.Web.HttpApplication.IExecutionStep.Execute() +606
   System.Web.HttpApplication.ExecuteStep(IExecutionStep step, Boolean& completedSynchronously) +288

关于第一个例外-我没有DbProviderFactories节在我的web.config

关于第二个-我发现的唯一一件事是，它可能是由于缺少"EntityFramework.SqlServer.dll"造成的，但这不是我的情况-它在那里