A similar question was asked and answered about a year ago, but was either a different issue (everything was in beta) or misdiagnosed. It\'s located here: MSbuild task fails
TFS uses a set of properties to control the names of the solutions and configurations to build ( iterate through ). For each combination of solution and configuration it then uses the project dependencies / build order to control the order of the projects getting built. It's possible that your EXE/DLL's are AnyCPU and that your WiX is x86 and that although the WiX has a dependency on the EXE/DLL the x86 is built before your AnyCPU. Or maybe they are even in different solutions so it's kind of hard to tell without looking at your source but that's basically how it works.