Issue
After installing BizTalk 2013, just to check I started to create a project with name as Test. Then added a schema named Test with Root tag named as Test and two elements. Signed the project and tried to build it and following error appeared.
To find out the problem, I went through the properties of the schema and found that Namespace and Type name is same. Well I don’t the exact reason but it seems having same namespace and type name causes ambiguity in resolution.