Unable to copy file reference.dll to bin/reference.dll. The process cannot access the file reference.dll because it is being used by another process

Question

For one of my ASP.NET 3.5 applications, every single time I try to build the web app, it throws the following build errors in Visual Studio 2008:

Error 16

Answer 1

I'm assuming you already know it's VS2008 which is locking the files. You can try running MSBuild from the command line and see if the problems disappear. Unfortunately Visual Studio can keep files locked when it shouldn't, in some hard-to-predict scenarios.