Compiler error “cannot resolve symbol” with nested namespaces

Question

I have reduced my problem to the following code.

using WeinCad.Plugin.MoineauMachinePath;
namespace WeinCad.Plugin.Foo
{
    public class Foo
    {
         // This line is a compiler error
         // (Cannot resolve symbol MoineauMachinePath )
         private WeinCad.Plugin.MoineauMachinePath.MachinePathSolverPropertiesViewModel X;

         // Implicity referenced it is ok
         private MachinePathSolverPropertiesViewModel Y;

    }
}

If I use an explicit reference to a class then I am getting a compiler error. To prove the namespace is correct I also import the namespace into scope and reference the class implicitly. Only the explicit reference is in error.

EDIT

The intellisense shows that there is a namespace nested double like so. That will be the source of the problem. Not sure how it code there.

EDIT

Source of the problem was a corrupted Resources.Designer.cs file.

//------------------------------------------------------------------------------
// <auto-generated>
//     This code was generated by a tool.
//     Runtime Version:4.0.30319.18444
//
//     Changes to this file may cause incorrect behavior and will be lost if
//     the code is regenerated.
// </auto-generated>
//------------------------------------------------------------------------------

namespace WeinCad.Plugin.WeinCad.Plugin.BasicFolders.Properties
{
    using System;

Not sure how this happened. Deleting the Resources file and then recreating it I get

//------------------------------------------------------------------------------
// <auto-generated>
//     This code was generated by a tool.
//     Runtime Version:4.0.30319.18444
//
//     Changes to this file may cause incorrect behavior and will be lost if
//     the code is regenerated.
// </auto-generated>
//------------------------------------------------------------------------------

namespace WeinCad.Plugin.BasicFolders.Properties {
    using System;

without the nasty duplicate. It's still an open question on how this happened.

Answer 1

That error message suggests that there is a WeinCad.Plugin inside the current scope, ie either WeinCad.Plugin.Foo.Foo.WeinCad.Plugin , or WeinCad.Plugin.Foo.WeinCad.Plugin . When the compiler is looking for WeinCad.Plugin , it looks first at the local scopes, and only if it can't find a match does it look at the global scope.

The simplest and most correct fix for this is: don't have a scope that duplicates names inside itself (that is just asking for trouble). The other option is to explicitly specify the global scope, using the global:: prefix in front of the full type name, ie global::WeinCad.Plugin.Whatever .