System.AccessViolationException in .NET 4.0 while connecting to SQL Database

问题

I have created following code

    Dim ConnectionString As String = ConfigurationManager.ConnectionStrings("default").ConnectionString
    Dim con As New SqlConnection(ConnectionString)
    con.Open()
    Response.Write("Connection Opened<br/>")
    con.Close()
    Response.Write("Connection Closed<br/>")

in a web application project Target .NET Framework 4.0 but it is giving System.AccessViolationException i cannot understand why.

if i change the target Framework to .NET 3.0 then the code runs fine.

Below is the detailed exception

System.AccessViolationException was unhandled
HResult=-2147467261
Message=Attempted to read or write protected memory. This is often an indication that other memory is corrupt.
Source=System.Data
StackTrace:
   at SNIAddProvider(SNI_Conn* , ProviderNum , Void* )
   at SNINativeMethodWrapper.SNIAddProvider(SafeHandle pConn, ProviderEnum providerEnum, UInt32& info)
   at System.Data.SqlClient.TdsParser.ConsumePreLoginHandshake(Boolean encrypt, Boolean trustServerCert, Boolean integratedSecurity, Boolean& marsCapable)
   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 CorruptedMemoryTest._default.Page_Load(Object sender, EventArgs e) in E:\Azure Migration\AzureTest\CorruptedMemoryTest\default.aspx.vb:line 9
   at System.Web.UI.Control.OnLoad(EventArgs e)
   at System.Web.UI.Control.LoadRecursive()
   at System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint)
   at System.Web.UI.Page.ProcessRequest(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint)
   at System.Web.UI.Page.ProcessRequest()
   at System.Web.UI.Page.ProcessRequestWithNoAssert(HttpContext context)
   at System.Web.UI.Page.ProcessRequest(HttpContext context)
   at ASP.default_aspx.ProcessRequest(HttpContext context)
   at System.Web.HttpApplication.CallHandlerExecutionStep.System.Web.HttpApplication.IExecutionStep.Execute()
   at System.Web.HttpApplication.ExecuteStep(IExecutionStep step, Boolean& completedSynchronously)
   at System.Web.HttpApplication.ApplicationStepManager.ResumeSteps(Exception error)
   at System.Web.HttpApplication.System.Web.IHttpAsyncHandler.BeginProcessRequest(HttpContext context, AsyncCallback cb, Object extraData)
   at System.Web.HttpRuntime.ProcessRequestInternal(HttpWorkerRequest wr)
   at System.Web.HttpRuntime.ProcessRequestNoDemand(HttpWorkerRequest wr)
   at System.Web.HttpRuntime.ProcessRequest(HttpWorkerRequest wr)
   at Microsoft.VisualStudio.WebHost.Request.Process()
   at Microsoft.VisualStudio.WebHost.Host.ProcessRequest(Connection conn)
   at Microsoft.VisualStudio.WebHost.Host.ProcessRequest(Connection conn)
   at Microsoft.VisualStudio.WebHost.Server.OnSocketAccept(Object acceptedSocket)
   at System.Threading.QueueUserWorkItemCallback.WaitCallback_Context(Object state)
   at System.Threading.ExecutionContext.RunInternal(ExecutionContext executionContext, ContextCallback callback, Object state, Boolean preserveSyncCtx)
   at System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state, Boolean preserveSyncCtx)
   at System.Threading.QueueUserWorkItemCallback.System.Threading.IThreadPoolWorkItem.ExecuteWorkItem()
   at System.Threading.ThreadPoolWorkQueue.Dispatch()
   at System.Threading._ThreadPoolWaitCallback.PerformWaitCallback()
   InnerException: 

回答1:

I just spent a week tearing my hair out and trying all sorts of desperate measures. But I was finally able to fix this by uninstalling a program that was monitoring network traffic (Cucusoft Net Guard). This program seems to interfere with something in the packet traffic and it was causing my error. Uninstalling this app fixed the problem, but, curiously, turning it off did not. It must have installed a low level filter that was in place and causing the problem even when the app was not running.

回答2:

After uninstall Cucusoft Net Guard, If someone have still problem then try

1. Run command prompt : Run as Administrator.

2. netsh winsock reset

After run this, restart your pc.

来源：https://stackoverflow.com/questions/16553239/system-accessviolationexception-in-net-4-0-while-connecting-to-sql-database