A while back I was building a WCF service that would be called by web sites and mobile devices. There ended up being weird bugs and due to firewall issues, I could not remote debug and had problems reproducing the issues too. Since the service was hosted in IIS I decided to use ELMAH to log unhandled exceptions. I spent a great deal of time trying to figure out how to get it working. There are a lot of articles discussing this topic but not a single one was complete or accurate enough to get the job done. So after I figured it out I decided to share it. I wrote a detailed article and posted it on DotNetSlackers.