If you want to know how to debug CLR exceptions using cdb then read this post.Exception code e0434352 is the exception code used internally by the CLR to represent most exceptions(*). Regardless of if you throw a System.NullReferenceException or a System.ArgumentException in C#, you'll throw a SEH exception e0434352 under the covers.A fun way to validate this theory is to watch what happens to the CLR exceptions settings in cdb. Fire up cdb, and see the state of clr exceptions: 0:000> .shell -ci "sx" findstr clr clr - CLR exception - second-chance break - not handledclrn - CLR notification...