System.InvalidCastException: QueryInterface for interface
I have a managed code that is calling unmanaged Com+ vb6 code , I always get this error for 1 component , other are working ok:
This component used to work ok..
One fact is that this is a webfarm cluster on several machines we are having the same problem
I traced the error on the web and it says (the closest) that this error might be due to threading conflicts (the unmanaged component is running in single app mode) but I repeat this used to work!