There is already an open DataReader associated with this Command which must be closed first.

Server Error in '/' Application.

There is already an open DataReader associated with this Command which must be closed first.

Description: An unhandled exception occurred.

Exception Details: System.InvalidOperationException: There is already an open DataReader associated with this Command which must be closed first.

Source Error:

An unhandled exception was generated during the execution of the current web request. Information regarding the origin and location of the exception can be identified using the exception stack trace below.

Stack Trace: 


[InvalidOperationException: There is already an open DataReader associated with this Command which must be closed first.]
   System.Data.SqlClient.SqlInternalConnectionTds.ValidateConnectionForExecute(SqlCommand command) +6733633
   System.Data.SqlClient.SqlCommand.ValidateCommand(String method, Boolean async) +308
   System.Data.SqlClient.SqlCommand.RunExecuteReader(CommandBehavior cmdBehavior, RunBehavior runBehavior, Boolean returnStream, String method, TaskCompletionSource`1 completion, Int32 timeout, Task& task, Boolean asyncWrite) +151
   System.Data.SqlClient.SqlCommand.RunExecuteReader(CommandBehavior cmdBehavior, RunBehavior runBehavior, Boolean returnStream, String method) +107
   System.Data.SqlClient.SqlCommand.ExecuteReader(CommandBehavior behavior, String method) +288
   System.Data.SqlClient.SqlCommand.ExecuteDbDataReader(CommandBehavior behavior) +180
   System.Data.Linq.SqlClient.SqlProvider.Execute(Expression query, QueryInfo queryInfo, IObjectReaderFactory factory, Object[] parentArgs, Object[] userArgs, ICompiledSubQuery[] subQueries, Object lastResult) +968
   System.Data.Linq.SqlClient.SqlProvider.ExecuteAll(Expression query, QueryInfo[] queryInfos, IObjectReaderFactory factory, Object[] userArguments, ICompiledSubQuery[] subQueries) +188
   System.Data.Linq.SqlClient.SqlProvider.System.Data.Linq.Provider.IProvider.Execute(Expression query) +500
   System.Data.Linq.Table`1.System.Linq.IQueryProvider.Execute(Expression expression) +50
   System.Linq.Queryable.FirstOrDefault(IQueryable`1 source, Expression`1 predicate) +490
   WebUI.Controllers.SucheController.FuelleSucheModel(SucheModel sm, SucheForm form) +19585
   WebUI.Controllers.SucheController.Pkw(String marke, Nullable`1 fahrzeugtyp) +2559
   lambda_method(Closure , ControllerBase , Object[] ) +171
   System.Web.Mvc.ReflectedActionDescriptor.Execute(ControllerContext controllerContext, IDictionary`2 parameters) +264
   System.Web.Mvc.ControllerActionInvoker.InvokeActionMethod(ControllerContext controllerContext, ActionDescriptor actionDescriptor, IDictionary`2 parameters) +39
   System.Web.Mvc.<>c__DisplayClass15.<InvokeActionMethodWithFilters>b__12() +124
   System.Web.Mvc.ControllerActionInvoker.InvokeActionMethodFilter(IActionFilter filter, ActionExecutingContext preContext, Func`1 continuation) +727830
   System.Web.Mvc.ControllerActionInvoker.InvokeActionMethodFilter(IActionFilter filter, ActionExecutingContext preContext, Func`1 continuation) +727830
   System.Web.Mvc.ControllerActionInvoker.InvokeActionMethodWithFilters(ControllerContext controllerContext, IList`1 filters, ActionDescriptor actionDescriptor, IDictionary`2 parameters) +309
   System.Web.Mvc.ControllerActionInvoker.InvokeAction(ControllerContext controllerContext, String actionName) +345