Cannot attach the file as database / The underlying provider failed on Open

Question

I have an MVC3 application using the Entity Framework. I haven't used this application in about a year. Recently, I opened it up on a new PC and tried to run in debug mode and hit the following exception/stack trace in debug. The main exceptions seem to be "Cannot attach the file as database" and "The underlying provider failed on Open". I searched for these errors on stack overflow and the answers I found don't seem to match this situation. For example, one of the answers for "Cannot attach the file as database" suggests that an old version of the db might be lying around on the local db, but I don't see any databases in the local database when I browse to localdb in visual studio.

I am looking for guidance about what to investigate next to troubleshoot this issue. Any suggestions?

The actual code where it fails is:

            var currentHunt = (from ph in this.repo.GetAllPuzzleHunts()
                           orderby ph.PuzzleHuntId descending
                           select ph).FirstOrDefault();

This is the first time the web app tries to get data from the db via the Entity Framework.

FWIW this machine has Entity Framework 6.0, and I'm using Visual Studio 2012.

Exception/Stack trace follow:

System.Data.DataException was unhandled by user code
  HResult=-2146233087
  Message=An exception occurred while initializing the database. See the InnerException for details.
  Source=EntityFramework
  StackTrace:
       at System.Data.Entity.Internal.InternalContext.PerformInitializationAction(Action action)
       at System.Data.Entity.Internal.InternalContext.PerformDatabaseInitialization()
       at System.Data.Entity.Internal.LazyInternalContext.<InitializeDatabase>b__4(InternalContext c)
       at System.Data.Entity.Internal.RetryAction`1.PerformAction(TInput input)
       at System.Data.Entity.Internal.LazyInternalContext.InitializeDatabaseAction(Action`1 action)
       at System.Data.Entity.Internal.LazyInternalContext.InitializeDatabase()
       at System.Data.Entity.Internal.InternalContext.Initialize()
       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.Data.Entity.Infrastructure.DbQuery`1.System.Collections.Generic.IEnumerable<TResult>.GetEnumerator()
       at System.Linq.Buffer`1..ctor(IEnumerable`1 source)
       at System.Linq.OrderedEnumerable`1.<GetEnumerator>d__0.MoveNext()
       at System.Linq.Enumerable.FirstOrDefault[TSource](IEnumerable`1 source)
       at GutolMvcApp.Controllers.HomeController.Index() in c:\Users\jordanat\Documents\Visual Studio 2012\Projects\Gutol\Gutol\GutolMvcApp\Controllers\HomeController.cs:line 25
       at lambda_method(Closure , ControllerBase , Object[] )
       at System.Web.Mvc.ActionMethodDispatcher.Execute(ControllerBase controller, Object[] parameters)
       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.Async.AsyncControllerActionInvoker.<>c__DisplayClass42.<BeginInvokeSynchronousActionMethod>b__41()
       at System.Web.Mvc.Async.AsyncResultWrapper.<>c__DisplayClass8`1.<BeginSynchronous>b__7(IAsyncResult _)
       at System.Web.Mvc.Async.AsyncResultWrapper.WrappedAsyncResult`1.End()
       at System.Web.Mvc.Async.AsyncControllerActionInvoker.EndInvokeActionMethod(IAsyncResult asyncResult)
       at System.Web.Mvc.Async.AsyncControllerActionInvoker.<>c__DisplayClass37.<>c__DisplayClass39.<BeginInvokeActionMethodWithFilters>b__33()
       at System.Web.Mvc.Async.AsyncControllerActionInvoker.<>c__DisplayClass4f.<InvokeActionMethodFilterAsynchronously>b__49()
  InnerException: System.Data.Entity.Core.EntityException
       HResult=-2146233087
       Message=The underlying provider failed on Open.
       Source=EntityFramework
       StackTrace:
            at System.Data.Entity.Core.EntityClient.EntityConnection.Open()
            at System.Data.Entity.Core.Objects.ObjectContext.EnsureConnection()
            at System.Data.Entity.Core.Objects.ObjectContext.ExecuteInTransaction[T](Func`1 func, IDbExecutionStrategy executionStrategy, Boolean startLocalTransaction, Boolean releaseConnectionOnSuccess)
            at System.Data.Entity.Core.Objects.ObjectQuery`1.<>c__DisplayClassb.<GetResults>b__9()
            at System.Data.Entity.SqlServer.DefaultSqlExecutionStrategy.Execute[TResult](Func`1 operation)
            at System.Data.Entity.Core.Objects.ObjectQuery`1.GetResults(Nullable`1 forMergeOption)
            at System.Data.Entity.Core.Objects.ObjectQuery`1.<System.Collections.Generic.IEnumerable<T>.GetEnumerator>b__0()
            at System.Lazy`1.CreateValue()
            at System.Lazy`1.LazyInitValue()
            at System.Lazy`1.get_Value()
            at System.Data.Entity.Internal.LazyEnumerator`1.MoveNext()
            at System.Linq.Enumerable.FirstOrDefault[TSource](IEnumerable`1 source)
            at System.Data.Entity.Core.Objects.ELinq.ObjectQueryProvider.<GetElementFunction>b__1[TResult](IEnumerable`1 sequence)
            at System.Data.Entity.Core.Objects.ELinq.ObjectQueryProvider.ExecuteSingle[TResult](IEnumerable`1 query, Expression queryRoot)
            at System.Data.Entity.Core.Objects.ELinq.ObjectQueryProvider.System.Linq.IQueryProvider.Execute[TResult](Expression expression)
            at System.Data.Entity.Internal.Linq.DbQueryProvider.Execute[TResult](Expression expression)
            at System.Linq.Queryable.FirstOrDefault[TSource](IQueryable`1 source)
            at System.Data.Entity.Internal.EdmMetadataRepository.QueryForModelHash(Func`2 createContext)
            at System.Data.Entity.Internal.InternalContext.QueryForModelHash()
            at System.Data.Entity.Internal.ModelCompatibilityChecker.CompatibleWithModel(InternalContext internalContext, ModelHashCalculator modelHashCalculator, Boolean throwIfNoMetadata)
            at System.Data.Entity.Internal.InternalContext.CompatibleWithModel(Boolean throwIfNoMetadata)
            at System.Data.Entity.Database.CompatibleWithModel(Boolean throwIfNoMetadata)
            at System.Data.Entity.CreateDatabaseIfNotExists`1.InitializeDatabase(TContext context)
            at System.Data.Entity.Internal.InternalContext.<>c__DisplayClasse`1.<CreateInitializationAction>b__d()
            at System.Data.Entity.Internal.InternalContext.PerformInitializationAction(Action action)
       InnerException: System.Data.SqlClient.SqlException
            HResult=-2146232060
            Message=Cannot attach the file 'C:\Users\...\Visual Studio 2012\Projects\Gutol\Gutol\GutolMvcApp\App_Data\PuzzleCollateral.mdf' as database 'PuzzleCollateral'.

Thanks for your help!

Answer 1

Try it this way:

https://stackoverflow.com/a/16339164/1390999

Open the "Developer Command Propmpt for VisualStudio" under your start/programs menu. Run the following commands:

sqllocaldb.exe stop v11.0

sqllocaldb.exe delete v11.0

After that, try to Start your MVC Application

Answer 2

Check your connection strings. If you're on a new computer you may need to change them somewhat or open a port in the firewall.

One simple way to get the proper connection string is to connect to the DB Server and view the properties.

1. Open SQL Server Object Explorer (View > SQL Server Object Explorer)
2. Connect to the DB Server (Click "Connect to Server" and enter "(LocalDB)\v11.0")
3. Right click on the appropriate DB and select "Properties"
4. View the connection string