NServiceBus Could not load file or assembly


I am getting the below error when i call "NServiceBus.Host.exe". The issue appears to be itextsharp.dll. I've read that i can use

"Configure.With(AllAssemblies.Except("itextsharp.dll"))... // rest of your config"

But i'm using the following sample and not sure where to add this property.



Unhandled Exception: Magnum.StateMachine.StateMachineException: Exception occurr ed in Topshelf.Internal.ServiceController1[[NServiceBus.Host.Internal.GenericHo st, NServiceBus.Host, Version=, Culture=neutral, PublicKeyToken=9fc386 479f8a226c]] during state Initial while handling OnStart ---> System.Exception: Exception when starting endpoint, error has been logged. Reason: Could not load file or assembly 'file:///D:\dev\MYSITE\MYSITE.EStore\EStore.Server\bin\Debug\itexts harp.dll' or one of its dependencies. Operation is not supported. (Exception fro m HRESULT: 0x80131515) at NServiceBus.Host.Internal.GenericHost.Start() in d:\BuildAgent-02\work\20b 5f701adefe8f8\src\host\NServiceBus.Host\Internal\GenericHost.cs:line 90 at Magnum.StateMachine.EventActionList1.Execute(T stateMachine, Event event, Object parameter) in :line 0 --- End of inner exception stack trace ---

Server stack trace: at Magnum.StateMachine.ExceptionActionDictionary1.HandleException(T stateMac hine, Event event, Object parameter, Exception exception) in :line 0 at Magnum.StateMachine.EventActionList1.Execute(T stateMachine, Event event, Object parameter) in :line 0 at Magnum.StateMachine.State1.RaiseEvent(T instance, BasicEvent1 eevent, Ob ject value) in :line 0 at Magnum.StateMachine.StateMachine`1.RaiseEvent(Event raised) in :line 0 at System.Runtime.Remoting.Messaging.StackBuilderSink._PrivateProcessMessage( IntPtr md, Object[] args, Object server, Int32 methodPtr, Boolean fExecuteInCont ext, Object[]& outArgs) at System.Runtime.Remoting.Messaging.StackBuilderSink.SyncProcessMessage(IMes sage msg, Int32 methodPtr, Boolean fExecuteInContext)

Exception rethrown at [0]: at System.Runtime.Remoting.Proxies.RealProxy.HandleReturnMessage(IMessage req Msg, IMessage retMsg) at System.Runtime.Remoting.Proxies.RealProxy.PrivateInvoke(MessageData& msgDa ta, Int32 type) at Topshelf.Internal.ServiceControllerProxy.Start() at Topshelf.Internal.ServiceCoordinator.Start() in d:\dev\open-source\topshel f\src\Topshelf\Internal\ServiceCoordinator.cs:line 54 at Topshelf.Internal.Hosts.ConsoleHost.Run() in d:\dev\open-source\topshelf\s rc\Topshelf\Internal\Hosts\ConsoleHost.cs:line 53 at NServiceBus.Host.Program.Main(String[] args) in d:\BuildAgent-02\work\20b5 f701adefe8f8\src\host\NServiceBus.Host\Program.cs:line 103

asked on Stack Overflow Dec 9, 2011 by frosty • edited Jan 29, 2016 by Peter

1 Answer


When NserviceBus host starts it tries to retrieve all types from assemblies you specify. In the sample you provide it uses NServiceBus.Configure.WithWeb() method. This is the same as to call NServiceBus.Configure.With(AppDomain.CurrentDomain.DynamicDirectory)

You get the excpetion because "itextsharp.dll" cannot be loaded to AppDomain (this is done by calling Assembly.LoadFrom(file.FullName) method).

To fix the issue, you may manually specify assemblies you need to scan by using one of NServiceBus.Configure.With() overloads.

answered on Stack Overflow Dec 12, 2011 by struhtanov

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