error in deisgner: The type 'HelixToolkit:HelixViewport3D' was not found. Verify that you are not missing an assembly reference and that all referenced assemblies have been built

Noylene wrote at 2013-01-21 14:47:

why do I have this error when opening XAML designer in any example project, or creating my own (adding reference manually or with Nuget, doesn't matter)?

In editor IntelliSense 'knows'  namespace HelixToolkit but don't know anything inside it

Beside this, project compiles and runs

VS2010, .Net 4.0

mannest wrote at 2013-01-25 06:47:

I have same problem.

Did you build HelixToolkit.Wpf_NET40 project in x64 platform?

In my case, no problem in x86 platform built.

Anyway, I don't know how to solve that problem in x64 platform.

Noylene wrote at 2013-01-25 07:07:

No, it's x86, WinXP

JohnSourcer wrote at 2013-01-25 07:10:

It's a known problem and doesn't affect the build. There are several reports of this and workarounds/solutions. Most common seems to be issues with 64 bit vs 32 bit builds and dll's.