Can't find the namespace "plugins" converting an old NV 2014 plugin to NV 2015

[genscripter]

I'm totally confused.  I've tried everything and can't get this to work.

I wrote a navisworks plugin in naviswroks 2014.  Our company started using navisworks 2015.  My plugins wouldn't even appear in the 2015 UI, when I put the dll and related files in the 2015 plugin folder.  

I opened the code and tried to replace the libraries (that shouldn't matter, because I would think the 2014 libraries should work in Navisworks 2015--If they don't work by design, that's a huge oversight.)  but replacing the libraries to the 2015 libraries doesn't work.  It says "The type or namespace 'Plugins' does not exist in namespace 'Autodesk.Navisworks.Api' (are you missing an assembly reference?)"   

I checked both Autodesk.Navisworks.Api.xml files in the following folders:

C:\Program Files\Autodesk\Navisworks Manage 2014

C:\Program Files\Autodesk\Navisworks Manage 2015

and they have the same tree structure with respect to the "Autodesk.Navisworks.Api.Plugins."  

I'd post a sample code, but it doesn't even get to the subroutines.  It literally crashes in the declarations.  Like this: 

using System;
using System.Windows.Forms;
using System.Collections.Generic;
using Autodesk.Navisworks;
using Autodesk.Navisworks.Api;
using Autodesk.Navisworks.Api.Plugins;

Whatever.  

I thought maybe my Visual Studio assembly was corrupt or something, so I literally opened a completely new VS assy, and started from scratch.  After rewriting the whole darn thing, it still says the Autodesk.Navisworks.Api.Plugins doesn't exist.  

So lots of fundamental questions:

How do I get the Plugins to work in 2015?

Why are my 2014 plugins not appearing in the 2015 UI Plugins Tab?

Is there a place on the internet that explains the changes between versions of Navisworks?

Whenever Autodesk releases a new version of Navisworks, do I have to recompile the dll's each time, reload the new libraries, and maintain and manage separate code for each version?  

It's impossible to have a productive workflow with these API's.  I can't make predictions on how much time it takes to write, revise, or upgrade code when there are so many weird obstacles like this.  Upgrading an older code to a new version should be automatic or less than an hours-worth of work.  

[swarochisa]

I had a similar problem but with other namespaces when I migrated to 2015. Changing the dotnet framework to 4.5.1(in my case) removed the error. I am not really sure what is wrong but try updating your dotnet framework to the latest version. Hope this works for you as it did for me.

[xiaodong_liang]

Hello,

firstly, sorry for the frustration you were having. currently, .NET API of Navisworks is NOT binary compatible in difference releases. So you will need to re-build the plugin with the assemblies of target release. In addition, 2015 API needs .NET framework 4.5. The same to what the contributor swarochisa indicated.

In addition, on runtime, the plugin will load the assemblies in Navisworks folder. so please set CopyLocal = false for Navisworks assemblies.