Team Foundation Server, apparently. Let’s say that some careless developer (me) forgot to close an XML tag. The aforementioned developer then checked in his build file and attempted to build it. At this point, I got a bit worried because TFS came back with the following error: TF42046: The build service used in the build process is not reachable. This error occurs when either the build machine is off-line,the required service is not running, Team Build is not installed on the build machine, Team Build is configured for a different Team Foundation Server or the network is not available. So, at this point I spent a few minutes attempting to debug this problem. It turns out that this problem can also be caused by silly developers leaving off closing XML tags in their hurry to finish the weekly build script. Why would Visual Studio throw back this seemingly unhelpful message? Probably because my XML was garbage and TFS simply refused to talk to me on the grounds that I am uncouth and trying to shout the XML equivalent of dirty words at it. Moral of the story: close your XML tags and don’t hurry.  Rick has informed me that I am a horrible developer and forgot to mention his involvement in this whole issue. So, Rick, thanks for helping me troubleshoot this problem. Read his blog, it’s at RickDoes.net. Did you notice that URL? He’s witty, much wittier than I.