Why does the TFS2013 MultiBuildTemplate throw all binaries to test into the same folder?

We have a Microsoft TeamFoundationServer 2013. Now we have many different TeamProjects with solutions.

Now I have to create a build-definition which builds many of those solutions at once. I can specify the build-output in the definition as follows: Solution Specific Build Outputs: True So this puts the build-outputs of every single project to a folder with the according name.

But now, I have to run the unit-tests for every solution. If I just enable it, many of the tests fail. This is because my BuildDefinition throws all binaries which it wants to test into the folder TestResults\Deploy_USERNAME 2015-03-26 11_30_00\Out. But now, there's the problem: Many of those projects contain a app.config for connection-strings (or a web.config). But obviously there can only be one such file in a single directory, so it overrides every file until the last project copies its app.config on top of all others. Now the unit-tests for that last project just run well, because it's got all necessary connection-string. But for all other projects, many will fail.

Is there an option to split those test-bins into different folders, just as the build-output? Or is there any other workaround for this problem?

Environment:

Team Foundation Server 2013

Windows Server 2012

Build-Template: MultiBuildTemplate.xaml