Debugging a third-party DLL in Visual Studio?

Question

I am using a third-party DLL. For some particular cases, a function in the DLL is throwing an exception. Is it possible to debug the DLL in the Visual Studio?

After

Answer 1

Something that has worked for me with debugging a couple of third-party libraries as well as .NET itself is WinDbg. It is an awesome debugger from Microsoft that I have used to troubleshoot some sticky problems that were occuring deep inside the framework.

You need to use the Son of Strike (SOS) extensions if it is a managed DLL. It can debug native also. You will need to know a bit about callstacks and assembly/CIL instructions to be good at using it. You should be able to determine the exception and what is causing it. We have used WinDbg/SOS to find for instance that in HttpWebResponse, if you are using Gzip compression to download a page and the server returns a bad Gzip header, .NET runs the decompression in the threadpool and a crash will take out your process. Happy debugging.