InvalidCastException: RPC_E_CANTCALLOUT_ININPUTSYNCCALL

Question

I'm building an application in C# that has a static class which initiate a COM class and handles some event handlers of another class that hooks keyboard. When I call a method of the COM class from a button event handler in my WPF window, the method works without any problems but when I call it in one of the event callbacks within my static class it throws following exception:

Unable to cast COM object of type 'BLAHBLAH' to interface type 'BLAHBLAH'. This operation failed because the QueryInterface call on the COM component for the interface with IID '{9DD6680B-3EDC-40DB-A771-E6FE4832E34A}' failed due to the following error: An outgoing call cannot be made since the application is dispatching an input-synchronous call. (Exception from HRESULT: 0x8001010D (RPC_E_CANTCALLOUT_ININPUTSYNCCALL)).

Can you please tell me, what this exception means and how can I solve it?

Answer 1

Refer this KB http://support.microsoft.com/kb/198996 Looks like it is because of threads(May not be user defined threads)