Object reference not set to an instance of an object. at System.Data.SqlClient.SqlConnection.TryOpenInner(TaskCompletionSource`1 retry) at System.Data.SqlClient.SqlConnection.TryOpen(TaskCompletionSource`1 retry) at System.Data.SqlClient.SqlConnection.Open() at System.Data.Entity.Infrastructure.Interception.InternalDispatcher`1.Dispatch[TTarget,TInterceptionContext](TTarget target, Action`2 operation, TInterceptionContext interceptionContext, Action`3 executing, Action`3 executed) at System.Data.Entity.Infrastructure.Interception.DbConnectionDispatcher.Open(DbConnection connection, DbInterceptionContext interceptionContext) at System.Data.Entity.SqlServer.DefaultSqlExecutionStrategy.<>c__DisplayClass1.b__0() at System.Data.Entity.SqlServer.DefaultSqlExecutionStrategy.Execute[TResult](Func`1 operation) at System.Data.Entity.Core.EntityClient.EntityConnection.Open() at System.Data.Entity.Core.Objects.ObjectContext.EnsureConnection(Boolean shouldMonitorTransactions) 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__DisplayClass7.b__5() 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..GetEnumerator>b__0() at System.Data.Entity.Internal.LazyEnumerator`1.MoveNext() at System.Linq.Enumerable.FirstOrDefault[TSource](IEnumerable`1 source) at DownmagazNet.Controllers.HomeController.HaveLink(String link) at DownmagazNet.Controllers.HomeController.ConvertSite_downmagaz_net(String content) at DownmagazNet.Controllers.HomeController.Proxy(String link)