NHibernate - SafeHandle Cannot be Null

Question

I am using NHibernate to connect to an Oracle database. Everything was fine until I suddenly started to get the strange Value cannot be null. Parameter name: SafeHandle cannot be null. error. I am not sure what I have changed to get this error and I do not know what exactly it means. Google does not give results too. Below is the full stack trace. Any ideas ?

Error happens when BuildSessionFactory is called:

 var x = Fluently.Configure()
        .Database(OracleClientConfiguration.Oracle10
            .ConnectionString(connectionString))
        .Mappings(m => m.FluentMappings.AddFromAssembly(Assembly.GetExecutingAssembly()))
        .BuildConfiguration();

    return x.BuildSessionFactory();

at System.StubHelpers.StubHelpers.SafeHandleAddRef(SafeHandle pHandle, Boolean& success) at System.Data.Common.UnsafeNativeMethods.OCIAttrSet(OciHandle trgthndlp, HTYPE trghndltyp, Byte[] attributep, UInt32 size, ATTR attrtype, OciHandle errhp) at System.Data.OracleClient.TracedNativeMethods.OCIAttrSet(OciHandle trgthndlp, Byte[] attributep, UInt32 size, ATTR attrtype, OciHandle errhp) at System.Data.OracleClient.OciHandle.SetAttribute(ATTR attribute, String value, OciErrorHandle errorHandle) at System.Data.OracleClient.OracleInternalConnection.OpenOnLocalTransaction(String userName, String password, String serverName, Boolean integratedSecurity, Boolean unicode, Boolean omitOracleConnectionName) at System.Data.OracleClient.OracleInternalConnection..ctor(OracleConnectionString connectionOptions) at System.Data.OracleClient.OracleConnectionFactory.CreateConnection(DbConnectionOptions options, Object poolGroupProviderInfo, DbConnectionPool pool, DbConnection owningObject) at System.Data.ProviderBase.DbConnectionFactory.CreatePooledConnection(DbConnection owningConnection, DbConnectionPool pool, DbConnectionOptions options) at System.Data.ProviderBase.DbConnectionPool.CreateObject(DbConnection owningObject) at System.Data.ProviderBase.DbConnectionPool.UserCreateRequest(DbConnection owningObject) at System.Data.ProviderBase.DbConnectionPool.GetConnection(DbConnection owningObject) at System.Data.ProviderBase.DbConnectionFactory.GetConnection(DbConnection owningConnection) at System.Data.ProviderBase.DbConnectionClosed.OpenConnection(DbConnection outerConnection, DbConnectionFactory connectionFactory) at System.Data.OracleClient.OracleConnection.Open() at NHibernate.Connection.DriverConnectionProvider.GetConnection() at NHibernate.Tool.hbm2ddl.SuppliedConnectionProviderConnectionHelper.Prepare() at NHibernate.Tool.hbm2ddl.SchemaMetadataUpdater.GetReservedWords(Dialect dialect, IConnectionHelper connectionHelper) at NHibernate.Tool.hbm2ddl.SchemaMetadataUpdater.Update(ISessionFactory sessionFactory) at NHibernate.Impl.SessionFactoryImpl..ctor(Configuration cfg, IMapping mapping, Settings settings, EventListeners listeners) at NHibernate.Cfg.Configuration.BuildSessionFactory() at Models.SessionFactory.CreateOracleConnection(String connectionString) in c:\Users\CMENGU\Projects\TNT\Models\SessionManager.cs:line 21 at TNT.SessionManager.InitOracleFactory() in c:\Users\CMENGU\Projects\TNT\TNT\SessionManager.cs:line 29 at TNT.Program.Main() in c:\Users\CMENGU\Projects\TNT\TNT\Program.cs:line 30 at System.AppDomain._nExecuteAssembly(RuntimeAssembly assembly, String[] args) at System.AppDomain.ExecuteAssembly(String assemblyFile, Evidence assemblySecurity, String[] args) at Microsoft.VisualStudio.HostingProcess.HostProc.RunUsersAssembly()
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.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state) at System.Threading.ThreadHelper.ThreadStart()

Both the SafeHandle and other parts of the error point to an issue with the connnection. Make sure the Db is Ok, that nobody changed a setting or a schema etc. — Henk Holterman
@HenkHolterman Nothing works. DB is OK. I can connect with Toad and everyone else in my team can run the code successfully. Not sure what is going on — Cemre Mengü
That all points to a problem in your configuration, not in your code. I'm no Oracle expert but try to find out what has changed. Something has. Driver DLLs, listener configs, ... — Henk Holterman

Cemre Mengü Cemre Mengü · Accepted Answer · 2015-03-12T23:22:20

It turns out that it was the visual studio 2015 preview that was somehow messing up something related to oracle libraries which led to this error. I had to reformat my pc couple of times until I understood whats going on.

NHibernate - SafeHandle Cannot be Null

1 Answers