Created Unassigned: I register R.NET relevant dll in GAC, program compile error [179]

Hi, I register R.NET relevant dll in GAC.
R.NET relevant dll includes RDotNet.dll, RDotNet.NativeLibrary.dll, and DynamicInterop.dll.

But c# program compile error.
"The type 'DynamicInterop.UnmanagedDll' is defined in an assembly that is not referenced. You must add a reference to assembly 'DynamicInterop, Version=0.7.4.0, Culture=neutral, PublicKeyToken=null'"

I sure the version of DynamicInterop.dll is correct

Thanks for your help.