I developed a NXOpen application in .Net. I have added one custom DLL as reference to my application. In visual studio i have given copy to local as false. I have got an error saying Assembly not found. When i made copy to local true it worked. In my Application directory the referenced DLL got copied. My question is why this is not the case for NXOpen DLLs. Though i have added NXOpen DLL as reference, I have done copy to local false and none of my NXOpen DLLs are in my application directory. But still my application worked. I do not know the reason. Could any one help me to understand this issue ?