MSBuild from command line errors - Reference required to System.Xml

I'm creating a batch script which will get latest version of the code of an application, then build it using msbuild. Everything works until the msbuild part. Here's the line that runs msbuild:

C:\WINDOWS\Microsoft.NET\Framework\v3.5\msbuild.exe "code/Solution.sln" /p:Configuration="Debug"

And the thing errors al开发者_StackOverflowl over the place - all the errors say something like:

C:\code\project1\codefile1.vb(882): error BC30009: Reference required to assembly 'System.Xml, Version=2.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089' containing the implemented interface 'System.Xml.Serialization.IXmlSerializable'. Add one to your project.

Everything builds without errors from from Visual Studio 2008. What's going on here?

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This is probably most detailed descriptions on what is going wrong:

MSBuild Can't Find Secondary References

Resolving Binary References in MSBuild

In short: Your project references assembly X. X contains a class, that implements interface from assembly Y. Your project does not reference Y, so MSBuild fails. Studio acts a bit smarter and finds the second level reference.

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Do just what it says and add a reference to System.Xml to your project.

Project->Add Reference