Why would you create an instance of the Outlook.Aplication object if you can
get it drectly from Outlook?
Besides being easier, that instance of the Outlook.Aplication object will
not be subject to the security prompts.

--
Dmitry Streblechenko (MVP)
http://www.dimastr.com/
OutlookSpy - Outlook, CDO
and MAPI Developer Tool
-
"John Yovas" wrote in message
...
We get this error only in one of our users PC with office 2003 we tried re
Reinstalling the Office 2003 Primary InterOp Assemblies also. Why should
this happen in only one users desktop when we have this add-in running on
100 of other workstation ?

Microsoft.Office.Interop.Outlook.Application oApplication = null;

try

{

comboBox_Folder.Items.Clear();

Type oType = Type.GetTypeFromProgID("Outlook.Application");

if (oType != null)

oApplication =
(Microsoft.Office.Interop.Outlook.Application)Acti vator.CreateInstance(oType);



Unable to cast object of type 'System.__ComObject' to type
'Microsoft.Office.Interop.Outlook.ApplicationClass '.
at
System.Runtime.Remoting.RemotingServices.AllocateU ninitializedObject(RuntimeType
objectType)
at
System.Runtime.Remoting.RemotingServices.AllocateU ninitializedObject(Type
objectType)
at
System.Runtime.Remoting.Activation.ActivationServi ces.CreateInstance(Type
serverType)
at
System.Runtime.Remoting.Activation.ActivationServi ces.IsCurrentContextOK(Type
serverType, Object[] props, Boolean bNewObj)
at System.RuntimeTypeHandle.CreateInstance(RuntimeTyp e type, Boolean
publicOnly, Boolean noCheck, Boolean& canBeCached, RuntimeMethodHandle&
ctor, Boolean& bNeedSecurityCheck)
at System.RuntimeType.CreateInstanceSlow(Boolean publicOnly, Boolean
fillCache)
at System.RuntimeType.CreateInstanceImpl(Boolean publicOnly, Boolean
skipVisibilityChecks, Boolean fillCache)
at System.Activator.CreateInstance(Type type, Boolean nonPublic)

TIA
John