C# 实体框架-仅在我第一次运行程序时提供IncompatibleException

我的程序中有一个非常严重的错误，我首先使用实体框架代码，每次我运行程序并在第一次获得ProviderIncompatibleException时访问DbContext，但是如果我退出程序并再次运行它，一切正常。完全例外的情况是：

 System.Data.Entity.Core.ProviderIncompatibleException was unhandled
  HResult=-2146233087
  Message=An error occurred while getting provider information from the database. This can be caused by Entity Framework using an incorrect connection string. Check the inner exceptions for details and ensure that the connection string is correct.
  Source=EntityFramework
  StackTrace:
       at System.Data.Entity.Utilities.DbProviderServicesExtensions.GetProviderManifestTokenChecked(DbProviderServices providerServices, DbConnection connection)
       at System.Collections.Concurrent.ConcurrentDictionary`2.GetOrAdd(TKey key, Func`2 valueFactory)
       at System.Data.Entity.Infrastructure.DefaultManifestTokenResolver.ResolveManifestToken(DbConnection connection)
       at System.Data.Entity.DbModelBuilder.Build(DbConnection providerConnection)
       at System.Data.Entity.Internal.LazyInternalContext.CreateModel(LazyInternalContext internalContext)
       at System.Data.Entity.Internal.RetryLazy`2.GetValue(TInput input)
       at System.Data.Entity.Internal.LazyInternalContext.InitializeContext()
       at System.Data.Entity.Internal.InternalContext.GetEntitySetAndBaseTypeForType(Type entityType)
       at System.Data.Entity.Internal.Linq.InternalSet`1.Initialize()
       at System.Data.Entity.Internal.Linq.InternalSet`1.GetEnumerator()
       at System.Collections.Generic.List`1..ctor(IEnumerable`1 collection)
       at System.Linq.Enumerable.ToList[TSource](IEnumerable`1 source)
       at IEX.ManagementServer.Monitor.IMSMonitor.MonitoringManager.Start() in C:\Develop\IEX\trunk\IEX.ManagementServer\IEX.ManagementServer.Monitor\IMSMonitor\MonitoringManager.cs:line 209
       at IEX.ManagementServer.WebServices.Host.Mediator.Initialize(Boolean dropAlways) in C:\Develop\IEX\trunk\IEX.ManagementServer\IEX.ManagementServer.WebServices.Host\Mediator.cs:line 49
       at IEX.ManagementServer.WebServices.Host.Program.Main(String[] args) in C:\Develop\IEX\trunk\IEX.ManagementServer\IEX.ManagementServer.WebServices.Host\Program.cs:line 51
  InnerException: System.Data.Entity.Core.ProviderIncompatibleException
       HResult=-2146233087
       Message=The provider did not return a ProviderManifestToken string.
       Source=EntityFramework
       StackTrace:
            at System.Data.Entity.Core.Common.DbProviderServices.GetProviderManifestToken(DbConnection connection)
            at System.Data.Entity.Utilities.DbProviderServicesExtensions.GetProviderManifestTokenChecked(DbProviderServices providerServices, DbConnection connection)
       InnerException: System.Data.SqlClient.SqlException
            HResult=-2146232060
            Message=A network-related or instance-specific error occurred while establishing a connection to SQL Server. The server was not found or was not accessible. Verify that the instance name is correct and that SQL Server is configured to allow remote connections. (provider: SQL Network Interfaces, error: 26 - Error Locating Server/Instance Specified)
            Source=.Net SqlClient Data Provider
            ErrorCode=-2146232060
            Class=20
            LineNumber=0
            Number=-1
            Server=""
            State=0
            StackTrace:
                 at System.Data.SqlClient.SqlInternalConnection.OnError(SqlException exception, Boolean breakConnection, Action`1 wrapCloseInAction)
                 at System.Data.SqlClient.TdsParser.ThrowExceptionAndWarning(TdsParserStateObject stateObj, Boolean callerHasConnectionLock, Boolean asyncClose)
                 at System.Data.SqlClient.TdsParser.Connect(ServerInfo serverInfo, SqlInternalConnectionTds connHandler, Boolean ignoreSniOpenTimeout, Int64 timerExpire, Boolean encrypt, Boolean trustServerCert, Boolean integratedSecurity, Boolean withFailover)
                 at System.Data.SqlClient.SqlInternalConnectionTds.AttemptOneLogin(ServerInfo serverInfo, String newPassword, SecureString newSecurePassword, Boolean ignoreSniOpenTimeout, TimeoutTimer timeout, Boolean withFailover)
                 at System.Data.SqlClient.SqlInternalConnectionTds.LoginNoFailover(ServerInfo serverInfo, String newPassword, SecureString newSecurePassword, Boolean redirectedUserInstance, SqlConnectionString connectionOptions, SqlCredential credential, TimeoutTimer timeout)
                 at System.Data.SqlClient.SqlInternalConnectionTds.OpenLoginEnlist(TimeoutTimer timeout, SqlConnectionString connectionOptions, SqlCredential credential, String newPassword, SecureString newSecurePassword, Boolean redirectedUserInstance)
                 at System.Data.SqlClient.SqlInternalConnectionTds..ctor(DbConnectionPoolIdentity identity, SqlConnectionString connectionOptions, SqlCredential credential, Object providerInfo, String newPassword, SecureString newSecurePassword, Boolean redirectedUserInstance, SqlConnectionString userConnectionOptions)
                 at System.Data.SqlClient.SqlConnectionFactory.CreateConnection(DbConnectionOptions options, DbConnectionPoolKey poolKey, Object poolGroupProviderInfo, DbConnectionPool pool, DbConnection owningConnection, DbConnectionOptions userOptions)
                 at System.Data.ProviderBase.DbConnectionFactory.CreatePooledConnection(DbConnectionPool pool, DbConnectionOptions options, DbConnectionPoolKey poolKey, DbConnectionOptions userOptions)
                 at System.Data.ProviderBase.DbConnectionPool.CreateObject(DbConnectionOptions userOptions)
                 at System.Data.ProviderBase.DbConnectionPool.UserCreateRequest(DbConnectionOptions userOptions)
                 at System.Data.ProviderBase.DbConnectionPool.TryGetConnection(DbConnection owningObject, UInt32 waitForMultipleObjectsTimeout, Boolean allowCreate, Boolean onlyOneCheckConnection, DbConnectionOptions userOptions, DbConnectionInternal& connection)
                 at System.Data.ProviderBase.DbConnectionPool.TryGetConnection(DbConnection owningObject, TaskCompletionSource`1 retry, DbConnectionOptions userOptions, DbConnectionInternal& connection)
                 at System.Data.ProviderBase.DbConnectionFactory.TryGetConnection(DbConnection owningConnection, TaskCompletionSource`1 retry, DbConnectionOptions userOptions, DbConnectionInternal& connection)
                 at System.Data.ProviderBase.DbConnectionClosed.TryOpenConnection(DbConnection outerConnection, DbConnectionFactory connectionFactory, TaskCompletionSource`1 retry, DbConnectionOptions userOptions)
                 at System.Data.SqlClient.SqlConnection.TryOpen(TaskCompletionSource`1 retry)
                 at System.Data.SqlClient.SqlConnection.Open()
                 at System.Data.Entity.SqlServer.DefaultSqlExecutionStrategy.<>c__DisplayClass1.<Execute>b__0()
                 at System.Data.Entity.SqlServer.DefaultSqlExecutionStrategy.Execute[TResult](Func`1 operation)
                 at System.Data.Entity.SqlServer.SqlProviderServices.UsingConnection(DbConnection sqlConnection, Action`1 act)
                 at System.Data.Entity.SqlServer.SqlProviderServices.UsingMasterConnection(DbConnection sqlConnection, Action`1 act)
                 at System.Data.Entity.SqlServer.SqlProviderServices.GetDbProviderManifestToken(DbConnection connection)
                 at System.Data.Entity.Core.Common.DbProviderServices.GetProviderManifestToken(DbConnection connection)
            InnerException: 

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有人帮忙吗？

我知道这是一条旧线。但是，您是否正试图在运行时更改app.config文件

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这件事发生在我身上，@Evk给了我一个关于正在发生的事情的描述。

你说的第一次是什么意思？启动程序，关闭它，然后重新启动？当错误再次发生时？当我第一次启动它时。。。开始->发生错误，停止，开始->一切正常…感兴趣的错误是：HResult=-2146232060 Message=与SQL Server建立连接时发生网络相关或特定于实例的错误。找不到服务器或无法访问服务器。验证实例名称是否正确，以及SQL Server是否配置为允许远程连接。提供程序：SQL网络接口，错误：26-定位指定的服务器/实例时出错