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Hi Devart Team,

Wish you all Happy New Year!!!


We have developed a web application using Asp.Net MVC3 framework with Devart Entity Model.
The application has been running without any issues on Window 2003 Server.

Recently, We upgraded Server OS with Windows Server 2012 version, and we hosted the same web application on Windows 2012 server (64bit).

The problem that we are facing is,
we are not able to fetch the records from the oracle table which has the column with the type of 'CLOB'.


Kindly give us solution for this issue.


Tools Information:

.NET 4.0
Asp.Net MVC3
Devart Professional Edition (Version: 6.30.165.0)
Windows Server 2012
IIS 8.5
Oracle 11g


We found following "Trace Information" using DebugDiagx64 tool.

System.AccessViolationException:
Attempted to read or write protected memory. This is often an indication that other memory is corrupt.


at OciDynamicType.nativeOCILobGetLength(HandleRef , HandleRef , IntPtr , Int32& )
at OciDynamicType.OCILobGetLength(HandleRef , HandleRef , IntPtr , Int32& )
at Devart.Data.Oracle.au.k()
at Devart.Data.Oracle.OracleLob.ReadLobCache()
at Devart.Data.Oracle.au.b()
at Devart.Data.Oracle.ak.u(Byte[] A_0, Int32 A_1, Int32 A_2)
at lambda_method(Closure , Shaper )
at System.Data.Common.Internal.Materialization.Shaper.HandleEntityAppendOnly[TEntity](Func`2 constructEntityDelegate, EntityKey entityKey, EntitySet entitySet)
at lambda_method(Closure , Shaper )
at System.Data.Common.Internal.Materialization.Coordinator`1.ReadNextElement(Shaper shaper)
at System.Data.Common.Internal.Materialization.Shaper`1.SimpleEnumerator.MoveNext()
at System.Linq.Enumerable.FirstOrDefault[TSource](IEnumerable`1 source)
at System.Linq.Queryable.FirstOrDefault[TSource](IQueryable`1 source)
at G2_BackOffice.Models.LoginGestPayModel.FetchNotificationContents(Int64 idLanguage)
at G2_BackOffice.Areas.Common.Controllers.NotificationController.ShowNotification()
at lambda_method(Closure , ControllerBase , Object[] )
at System.Web.Mvc.ReflectedActionDescriptor.Execute(ControllerContext controllerContext, IDictionary`2 parameters)
at System.Web.Mvc.ControllerActionInvoker.InvokeActionMethod(ControllerContext controllerContext, ActionDescriptor actionDescriptor, IDictionary`2 parameters)
at System.Web.Mvc.ControllerActionInvoker.<>c__DisplayClass15.b__12()
at System.Web.Mvc.ControllerActionInvoker.InvokeActionMethodFilter(IActionFilter filter, ActionExecutingContext preContext, Func`1 continuation)
at System.Web.Mvc.ControllerActionInvoker.InvokeActionMethodFilter(IActionFilter filter, ActionExecutingContext preContext, Func`1 continuation)
at System.Web.Mvc.ControllerActionInvoker.InvokeActionMethodFilter(IActionFilter filter, ActionExecutingContext preContext, Func`1 continuation)
at System.Web.Mvc.ControllerActionInvoker.InvokeActionMethodWithFilters(ControllerContext controllerContext, IList`1 filters, ActionDescriptor actionDescriptor, IDictionary`2 parameters)
at System.Web.Mvc.ControllerActionInvoker.InvokeAction(ControllerContext controllerContext, String actionName)
at System.Web.Mvc.Controller.ExecuteCore()
at System.Web.Mvc.ControllerBase.Execute(RequestContext requestContext)
at System.Web.Mvc.MvcHandler.<>c__DisplayClass6.<>c__DisplayClassb.b__5()
at System.Web.Mvc.Async.AsyncResultWrapper.<>c__DisplayClass1.b__0()
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.Hosting.ISAPIRuntime.ProcessRequest(IntPtr ecb, Int32 iWRType)




Regards,
P. Mohan

There were several fixes of the AccessViolationException problem since 6.30.165 (revision history):

• The bug with AccessViolationException when finalizing an open OracleDataReader in the OCI mode is fixed (8.4.191 26-Jun-14)
• The bug with AccessViolationException in heavy load long-running applications is fixed (7.7.267 20-Jun-13)
• The bug with generating AccessViolationException when retrieving data via OracleDataReader using the x64 version of Oracle client is fixed (7.2.96 04-Oct-12)

Please try using the latest (8.4.313) build of dotConnect for Oracle. If you do not have access to the registered version, contact us to get a link to an extended trial for test purposes.

Hi Shalex,

We downloaded latest version of "dotConnect for Oracle professional(8.4.313.0 trial)" and installed on my machine.

Now the application runs quite well on my machine, when I host it on Test Server (Windows 2012 - 64bit), it shows "License not found error" as below

"License not found. Please view "Licensing" topic in LinqConnect documentation for details or contact Devart technical support. ***,Inner Exception-***,Trace - at Devart.Data.Oracle.Linq.Provider.OracleDataProvider.Initialize(Object connection)
at Devart.Data.Linq.DataContext.a(Object A_0, MappingSource A_1, Type A_2)"

I am getting license error even though I have included "license.licx" using License wizard. License.licx that I have included has the following content
"Devart.Data.Oracle.OracleConnection, Devart.Data.Oracle, Version=8.4.313.0, Culture=neutral, PublicKeyToken=09af7300eec23701"

Note: I am using both Devart Entity Model and Devart LinqConnect Model in my web application.

Kindly guide me to resolve this issue.

Regards,
Mohan

License not found. Please view "Licensing" topic in LinqConnect documentation for details or contact Devart technical support.

This error may occur in case when LinqConnect trial assemblies are used. Please tell us whether you are using LinqConnect Trial edition, too?

Generally, this exception means that the license resource was not added to your application. Please try adding the license resource again as it is described here:
http://www.devart.com/dotconnect/oracle ... nsing.html
http://www.devart.com/dotconnect/oracle ... g.html#asp

If this doesn't help, please create a test project and add a license resource to it. Build the project and send the result file to us.