Common error when connecting to IBM Websphere MQ from ASP.NET

Problem

When connecting to an IBM WebSphere MQ queue using the WebSPhere MQ classes for .NET from within an ASP.NET application, you might run into the following error:

General Exception: The type initializer for 'IBM.WMQ.MQQueueManager' threw an exception.

When investigating the error a bit further we find the following error in the Windows EventViewer:

An unhandled exception occurred and the process was terminated.
Application ID: /LM/W3SVC/1/ROOT/HealthCheckMQSeriesService
Process ID: 4972
Exception: System.Reflection.TargetInvocationException
Message: Exception has been thrown by the target of an invocation.
StackTrace:    at System.RuntimeTypeHandle.CreateInstance(RuntimeType type, Boolean publicOnly, Boolean noCheck, Boolean& canBeCached, RuntimeMethodHandleInternal& ctor, Boolean& bNeedSecurityCheck)
   at System.RuntimeType.CreateInstanceSlow(Boolean publicOnly, Boolean skipCheckThis, Boolean fillCache)
   at System.RuntimeType.CreateInstanceDefaultCtor(Boolean publicOnly, Boolean skipVisibilityChecks, Boolean skipCheckThis, Boolean fillCache)
   at System.Activator.CreateInstance(Type type, Boolean nonPublic)
   at System.RuntimeType.CreateInstanceImpl(BindingFlags bindingAttr, Binder binder, Object[] args, CultureInfo culture, Object[] activationAttributes)
   at System.Activator.CreateInstance(Type type, BindingFlags bindingAttr, Binder binder, Object[] args, CultureInfo culture)
   at System.RuntimeType.InvokeMember(String name, BindingFlags bindingFlags, Binder binder, Object target, Object[] providedArgs, ParameterModifier[] modifiers, CultureInfo culture, String[] namedParams)
   at IBM.WMQ.CommonServices.CreateCommonServices()
   at IBM.WMQ.CommonServices.TraceEntry(String objectId, UInt32 component, UInt32 method, Object[] parameters)
   at IBM.WMQ.MQQueueManager.Dispose(Boolean disposing)
   at IBM.WMQ.MQQueueManager.Finalize()

InnerException: System.DllNotFoundException
Message: Unable to load DLL 'amqxcs2.dll': The specified module could not be found. (Exception from HRESULT: 0x8007007E)
StackTrace:    at IBM.WMQ.MQCommonServices.xcsInitialize(UInt16 scope, UInt16 attributes, Byte[] charName, Byte[] charPrefix, xcsHPOOL& hPool)
   at IBM.WMQ.MQCommonServices.Initialize()

Solution

The solution is very simple.

In IIS go to the advanced settings of  application pool your application is running under.
Be sure that the “Load User Profile” property is set to true.

Run your application again and you should notice that the error disappeared.

Author: Christophe Verschuere