Compiler Error CS0104

'reference' is an ambiguous reference between 'identifier' and 'identifier'

Your program contains using directives for two namespaces and your code references a name that appears in both namespaces.

The following sample generates CS0104:

// CS0104.cs  
using x;  
using y;  
  
namespace x  
{  
   public class Test  
   {  
   }  
}  
  
namespace y  
{  
   public class Test  
   {  
   }  
}  
  
public class a  
{  
   public static void Main()  
   {  
      Test test = new Test();   // CS0104, is Test in x or y namespace?  
      // try the following line instead  
      // y.Test test = new y.Test();  
   }  
}