How do I fix MSB3073 error in my post-build event?

Playing around with different project properties, I found that the project build order was the problem. The project that generated the files I wanted to copy was built second, but the project that was running the batch file as a post-build event was built first, so I simply attached the build event to the second project instead, and it works just fine. Thanks for your help, everyone, though.

In my case, the dll I was creating by building the project was still in use in the background. I killed the application and then xcopy worked fine as expected.

Prefer the MsBuild "Copy" task in an AfterBuild target over a post-build event.

Append this Target into your project file and remove the PostBuildEvent.

<Target Name="AfterBuild">
    <Copy SourceFiles="C:\Users\scogan\Documents\Visual Studio 2012\Projects\Organizr\Server\bin\Debug\Organizr.Services.*" 
          DestinationFolder="C:\inetpub\wwwroot\AppServer\bin\" 
          OverwriteReadOnlyFiles="true" 
          SkipUnchangedFiles="false" />
</Target>

For what it's worth, the problem in my case was caused by using '/' as the directory separator in a copy command. Must use backslashes.