MSbuild fail (type or namespace name does not exist in the namespace)

Hi all, I'm having problems with MSbuild and I cannot make a successful build.

I have a VM with Visual Studio 2012 and 2013 Agents, I also installed Build Tools 2013.
I have msbuild configured like this:


I've been dealing with this problem for a week now and I don't know what else to do.
Here's the error log:


The solution builds fine on my laptop...

Thanks.